Further, the external environment sensor 21 in the above embodiment is described as being surrounded by air and the air being introduced into the casing 10. However, the configuration is not limited thereto, and any fluid such as water may be introduced into the casing 10. It should be noted that, depending on the fluid to be introduced, waterproof treatment needs to be separately applied to the electronic device 15 and the like.

Further, although the dew condensation state (the state in which dew is formed) is detected in the above embodiment, the state in which dew is likely to be formed (for example, degree of humidity) may be detected so that opening and closing of the ventilation port 40 is controlled in response to the detection result.

Further, although the artificial air aperture 30 is closed when the electronic device 15 is powered off in step S120 in the above embodiment, the artificial air aperture 30 may be open in the same step.

In the embodiments described above, the electronic device 15 can be provided in an appropriate environment.

• • 1 . . . ventilation control system
  • 10 . . . casing
  • 15 . . . electronic device
  • 21 . . . external environment sensor
  • 21 . . . environment sensor
  • 22 . . . internal environment sensor