PURPOSE: To prevent the malfunction and the damage to electronic parts even if a human body charged with static electricity touches the switch of a device by providing a discharge means and elastic means between a cover and a device main body.

CONSTITUTION: Hinges 8 are used as the fixing shafts 7 of a noise preventive cover, and in the vicinities of the fitted positions thereof metal-made springs as elastic means 4 made of a conductive material are provided. The metal-made springs are provided one piece each for the hinges 8. One of both sides of the spring is touched to a chassis earth 5 connected to the earth of a device main body, and the other touches a discharge plate 3. Thereby, by providing the elastic means 4, when a hand is detached from the cover after opening the cover, the cover is automatically closed by elastic force.