In a power seat operation device, a cam portion formed at a dial base has valleys and peaks that are alternately arranged in a row along a rotation direction of a dial so as to form an undulation in a radial direction. A slider is supported by the dial so as to be slidable in the radial direction. The slider is abutted against the cam portion by biasing force from a roller spring and fits into one out of the valleys so as to retain the dial at one of the rotary positions. During rotational operation of the dial, the slider crosses over at least one out of the peaks while elastically deforming the roller spring and sliding with respect to the dial.