What is claimed is:1. A light-emitting device comprising:a first substrate;a second substrate which is capable of transmitting an energy ray and is over the first substrate;a sealed object between the first substrate and the second substrate;a sealant surrounding the sealed object, the sealant attaching the first substrate to the second substrate; anda plurality of metal layers overlapping with the sealant, each of the plurality of metal layers comprising a metal element selected from aluminum, copper, chromium, tantalum, titanium, molybdenum, or tungsten and having higher reflectivity with respect to the energy ray than the first substrate,wherein the sealant includes a glass,wherein, in a top view of the light-emitting device, a first part of the sealant extends in a first direction, a second part of the sealant extends in a second direction substantially orthogonal to the first direction, and a corner of the sealant is located between the first part of the sealant and the second part of the sealant, andwherein the plurality of metal layers are arranged in stripe and obliquely intersect the corner of the sealant to cross both of the first part of the sealant and the second part of the sealant.2. The light-emitting device according to claim 1,wherein the sealed object is at least one of an electronic element, a light-emitting element including a layer containing a light-emitting organic compound, a circuit element, a memory element, and an arithmetic element.3. The light-emitting device according to claim 1,wherein the energy ray includes at least one of an electron beam, a light beam, a microwave beam, and an ultrasonic beam.4. The light-emitting device according to claim 1,wherein the first substrate is a glass substrate, a ceramic substrate, a metal substrate, a lamination of a resin substrate and an inorganic material, a substrate formed of fiberglass-reinforced plastics, or a substrate formed of a prepreg, andwherein the second substrate is a glass substrate, a ceramic substrate, a metal substrate, a lamination of a resin substrate and an inorganic material, a substrate formed of fiberglass-reinforced plastics, a substrate formed of a prepreg, a quartz substrate, a sapphire substrate, or a substrate formed of polyvinyl fluoride.5. The light-emitting device according to claim 1,wherein the plurality of metal layers comprises a connection terminal, an antenna, or a coil of the sealed object.6. A light-emitting device comprising:a first substrate;a second substrate;a sealant attaching the first substrate to the second substrate; anda plurality of metal layers overlapping with the sealant, each of the plurality of metal layers comprising a metal element selected from aluminum, copper, chromium, tantalum, titanium, molybdenum, or tungsten,wherein, in a top view of the light-emitting device, a first part of the sealant extends in a first direction, a second part of the sealant extends in a second direction substantially orthogonal to the first direction, and a corner of the sealant is located between the first part of the sealant and the second part of the sealant,wherein the plurality of metal layers are arranged in stripe and obliquely intersect the corner of the sealant to cross both of the first part of the sealant and the second part of the sealant, andwherein the plurality of metal layers obliquely intersecting the corner of the sealant are arranged at intervals which are different from intervals of the plurality of metal layers along the first part of the sealant and the second part of the sealant.7. The light-emitting device according to claim 6, wherein the sealant includes a glass.8. The light-emitting device according to claim 6,wherein the first substrate is a glass substrate, a ceramic substrate, a metal substrate, a lamination of a resin substrate and an inorganic material, a substrate formed of fiberglass-reinforced plastics, or a substrate faulted of a prepreg, andwherein the second substrate is a glass substrate, a ceramic substrate, a metal substrate, a lamination of a resin substrate and an inorganic material, a substrate formed of fiberglass-reinforced plastics, a substrate formed of a prepreg, a quartz substrate, a sapphire substrate, or a substrate formed of polyvinyl fluoride.9. The light-emitting device according to claim 6,wherein the plurality of metal layers comprises a connection terminal, an antenna, or a coil of a sealed object interposed between the first substrate and the second substrate.