PURPOSE: To simplify a structure, to reduce a processing cost, to improve the degree of freedoms of a design and to reduce in size a device by forming a shaft along one of peripheral surfaces of a protection cover, engaging the shaft inside U-shaped fittings provided with engaging protrusion outside both ends, and engaging the protrusion of the fittings by press-fitting in the mounting hole of a panel.

CONSTITUTION: A shaft 7 is formed along one of peripheral surfaces of a protection cover 5 for protecting an actuating component 4, the shaft 7 is engaged inside U-shaped fittings 8 having elasticity and provided with an engaging protrusion 9 outside both ends, and the protrusion 9 of the fittings 8 is engaged by press-fitting in the mounting hole 3 of a panel 1. In this case, even when the cover 5 is closed or opened, it can be locked in the state by a pulling force of the fittings 8 due to the elasticity. Accordingly, the component 4 in a recess 2 can be protected or operated. The rotating center of the cover 5 can be set to any of upper, lower, right and left sides. Thus, its structure can be simplified, a processing cost can be reduced, the degree of freedoms of a design can be improved, and a device can be reduced in size.