What is claimed is:1. A cooking appliance, comprising:at least one housing assembly;at least one cooking chamber formed in the housing assembly, the at least one cooking chamber including at least one loading opening and being configured to receive food introduced via the at least one loading opening;at least one microwave device associated with the at least one cooking chamber and configured to heat the food; andat least one cooking chamber door configured to close the at least one loading opening, the at least one cooking chamber door comprising at least one frame assembly and at least one window assembly,wherein the at least one frame assembly comprises a plurality of edges, at least one contact face at each of the edges on a side of the at least one cooking chamber door that faces the at least one cooking chamber when the at least one cooking chamber door is closed, at least one of the contact faces being an at least one extended contact face that is significantly larger than the remaining contact faces with respect to at least one geometric dimension, the at least one extended contact face being configured to rest against a corresponding contact portion on the at least one housing assembly when the at least one cooking chamber door is closed,wherein at least one stabilising device is provided on the at least one extended contact face so as to reinforce the at least one extended contact face,the cooking appliance farther comprising at least one technical component associated with the corresponding contact portion, wherein at least in regions the at least one technical component forms the corresponding contact portion.2. The cooking appliance of claim 1, wherein the at least one stabilising device comprises at least one metal sheet.3. The cooking appliance of claim 1, wherein the at least one stabilising device is formed integrally with the at least one extended contact face.4. The cooking appliance of claim 1, wherein the at least one stabilising device comprises at least one deformation of the at least one extended contact face.5. The cooking appliance of claim 4, wherein the at least one stabilising device comprises at least two deformations arranged substantially in parallel with one another.6. The cooking appliance of claim 4, wherein the at least one deformation is formed by at least one embossed portion in the at least one extended contact face.7. The cooking appliance of claim 6, wherein the at least one embossed portion comprises a concave groove.8. The cooking appliance of claim 4, wherein the at least one extended contact face has a longitudinal extension and a transverse extension, the at least one deformation extending along the longitudinal extension.9. The cooking appliance of claim 1, wherein at least a portion of the at least one frame assembly is associated with at least one wave trap device disposed somewhere other than on the at least one extended contact face.10. The cooking appliance of claim 9, wherein the at least one wave trap device is arranged on a side of the at least one extended contact face that faces the centre of the at least one cooking chamber door.11. The cooking appliance of claim 9, wherein at least one technical component is arranged in the corresponding contact portion and to the outside of the at least one wave trap device when the at least one cooking chamber door is closed.12. The cooking appliance of claim 1, wherein the at least one cooking chamber door comprises at least one cavity that adjoins at least a portion of the at least one extended contact face.13. The cooking appliance of claim 1, wherein at least a portion of the at least one extended contact face comprises a metal sheet.14. The cooking appliance of claim 13, wherein the metal sheet comprises a Cr—Ni steel sheet.15. The cooking appliance of claim 1, wherein at least one steam generation. device is associated with the at least one cooking chamber, the at least one steam generation device being configured to supply steam to the at least one cooking chamber.16. The cooking appliance of claim 15, wherein the at least one steam generation device comprises at least one water reservoir disposed in the corresponding contact portion.17. The cooking appliance of claim 16, wherein at least in regions the at least one water reservoir forms the corresponding contact portion.18. The cooking appliance of claim 1, wherein the at least one extended contact face is arranged on a. side edge of the at least one frame assembly.19. The cooking appliance of claim 1, wherein the at least one extended contact face has a transverse extension that is oriented substantially orthogonally to one of the plurality of edges of the at least one frame assembly.20. The cooking appliance of claim 19, wherein the transverse extension of the at least one extended contact face is larger than a transverse extension of one of the remaining contact faces at another of the plurality of edges of the at least one frame assembly.21. The cooking appliance of claim 19, wherein the transverse extension of the at least one extended contact face is at least twice as large as a transverse extension of one of the remaining contact faces at another of the plurality of edges of the at least one frame assembly.22. The cooking appliance of claim 19, wherein the at least one extended contact face has a transverse extension of at least 3 centimeters.23. The cooking appliance of claim 22, wherein the at least one extended contact face has a transverse extension of at least 5 centimeters but at most 20 centimeters.24. The cooking appliance of claim 1, wherein the at least one technical component is configured so as to be accessible to a user of the cooking appliance.25. The cooking appliance of claim 1, wherein the at least one technical component is arranged so as to be covered by the at least one cooking chamber door when the at least one cooking chamber door is closed.26. The cooking appliance of claim 1, wherein the at least one technical component is arranged on a side of the at least one housing assembly.27. The cooking appliance of claim 1, wherein the at least one technical component comprises at least one water reservoir configured to supply water to at least one steam generation device associated with the at least one cooking chamber, the at least one steam generation device being configured to supply steam to the at least one cooking chamber.28. The cooking appliance of claim 27, wherein the at least one water reservoir is configured so as to be removable from the cooking appliance.29. The cooking appliance of claim 1, wherein the at least one extended contact face has a transverse extension that is greater than or equal to a width of the at least one technical component.30. The cooking appliance of claim 29, wherein the at least one technical component comprises at least one water reservoir.31. A cooking appliance, comprising:at least one housing assembly;at least one cooking chamber formed in the housing assembly, the at least one cooking chamber including at least one loading opening and being configured to receive food introduced via the at least one loading opening;at least one microwave device associated with the at least one cooking chamber and configured to heat the food; andat least one cooking chamber door configured to close the at least one loading opening, the at least one cooking chamber door comprising at least one frame assembly and at least one window assembly,wherein the at least one frame assembly comprises a plurality of edges, at least one contact face at each of the edges on a side of the at least one cooking chamber door that faces the at least one cooking chamber when the at least one cooking chamber door is closed, at least one of the contact faces being an at least one extended contact face that is significantly larger than the remaining contact faces with respect to at least one geometric dimension, the at least one extended contact face being configured to rest against a corresponding contact portion on the at least one housing assembly when the at least one cooking chamber door is closed,wherein at least one stabilising device is provided on the at least one extended contact face so as to reinforce the at least one extended contact face,wherein the at least one extended contact face has a transverse extension that is oriented substantially orthogonally to one of the plurality of edges of the at least one frame assembly, andwherein the transverse extension of the at least one extended contact face is at least twice as large as a transverse extension of one of the remaining contact faces at another of the plurality of edges of the at least one frame assembly.32. A cooking appliance, comprising:at least one housing assembly;at least one cooking chamber formed in the housing assembly, the at least one cooking chamber including at least one loading opening and being configured to receive food introduced via the at least one loading opening;at least one microwave device associated with the at least one cooking chamber and configured to heat the food; andat least one cooking chamber door configured to close the at least one loading opening, the at least one cooking chamber door comprising at least one frame assembly and at least one window assembly,wherein the at least one frame assembly comprises a plurality of edges, at least one contact face at each of the edges on a side of the at least one cooking chamber door that faces the at least one cooking chamber when the at least one cooking chamber door is closed, at least one of the contact faces being an at least one extended contact face that is significantly larger than the remaining contact faces with respect to at least one geometric dimension, the at least one extended contact face being configured to rest against a corresponding contact portion on the at least one housing assembly when the at least one cooking chamber door is closed,wherein at least one stabilising device is provided on the at least one extended contact face so as to reinforce the at least one extended contact face,wherein at least one steam generation device is associated with the at least one cooking chamber, the at least one steam generation device being configured to supply steam to the at least one cooking chamber,wherein the at least one steam generation device comprises at least one water reservoir disposed in the corresponding contact portion, andwherein at least in regions the at least one water reservoir forms the corresponding contact portion.