To surely carry out an operation for focus change with respect to imaging even when a video camera is downsized.

A control section 13 of the switch unit 10 applied to the video camera respectively stores a voltage when a switch member 11 is located in a central required range 12a within a slide range, a voltage when the switch unit 10 is located at an end 12b at a telescopic end, and a voltage when the switch unit 10 is located at an end 12c at a wide end to a ROM 13a to detect a voltage attended with the movement of the switch member 11. Further, the control section 13 measures a time from the detection at the required range 12a to the detection at the end 12b or 12c, particularizes a kind of a signal in response to the measured time from a table stored in the ROM 13a, and outputs the signal of the particularized kind to be able to output the signal of the required kind even when the sliding range is short.