PURPOSE: To improve the restorability and operability of a movable operation element and prolong the life by providing the base end part of the movable operation element body almost in a rectangular prism shape, where a movable contact is formed, with hinge parts at three places which are the rear part and both sideward parts.

CONSTITUTION: A flexible operation sheet 17 is arranged on the top surfaces of support parts 19 and 21, formed along the lengthwise opening of the upper cabinet 13a of a scraper operation device 12, provided with plural projection parts 23 which protrude forward from the support part 21 at constant intervals. The cabinet 13 contains the movable operation body 18 which has the movable contact 16 at the front end across the thin hinge part 31 and a substrate 22 which has a fixed contact 20 opposite the movable contact 16. This movable operation body 18 is almost in the rectangular prism shape having the base end part 34 and the free end where the movable contact 16 is formed and the base end part is provided with the hinge parts 31 and 33 at the three places which are the rear part and both the sideward places. A deflecting force is therefore not concentrated on the rear end part even with a breadthwise slanting operation force.