PURPOSE: To make a projection part short and increase its strength by providing a repeating member, which presses a lid part opening/closure detection switch part by making the projection part provided on the lid part abut when the lid part is closed, between the projection part and a switch part.

CONSTITUTION: When the lid part 1 is placed at a closure position, a lock claw 9a engages a lock claw engagement part 1b to lock the lid part 1, but the tip part of the projection part 1a presses a top surface abutting part 3a1 as part of the top surface part 3a of the repeating member 3 at this time. Consequently, the member 3 moves down and the L-shaped projection part 3b formed on the member 3 presses the tip part 5a of the lid part opening/closure detection switch 5, so that the tip part 5a moves down. The switch part 5, therefore, detects the lid part 1 being at the closure position. Thus, the lid part opening/ closure detecting mechanism is provided with the member 3 and then the projection part 1a can be made short and increased in strength.