PURPOSE: To make a switched condition of the switch device displayable from a display opening portion and make very easy the assembly of the operation panel with respect to a substrate, by movably disposing a display panel in a guiding opening portion of a guide plate.

CONSTITUTION: A display plate 9 is movably disposed in a guiding opening portion 8 of a guide plate 7 clamped between an outer wall panel member 5 and a supporting plate 6, and the display panel 9 is integrally mounted to the member 5. An opening portion of the plate 6, an engaging hole 19 of the plate 9, and a display opening portion 10 of the member 5 are integrated together. Through mere passing therethrough of an operating member 4a of a slide switch device 4, it becomes possible to assemble the operation panel to an appliance body. This eliminates the time and labour of mounting the plate 9 to each switch device 4, makes easy the assembly at the time of, for example, manufacture, and enhances the working efficiency. Further, missing and losing the plate 9, and mounting it in opposite direction, do not happen. Namely, a switched condition of the switch device 4 is made displayable from the display opening portion 10, and the operation panel can be very easily mounted to a substrate 2 on which a plurality of devices 4, etc., are disposed.