Provided is a rotation detection device that detects a rotational direction and amount of a rotatable operation member. The detection device manages to reduce the rotation detection pitch while maintaining sufficient clearance for a rotation detection switch to operate. In other words, sufficient distance is given between rotation detection members such that the switch can accurately detect the movement from one member to the next. The rotatable operation member generally includes a plurality of switch driving sections that rotate in unison. A rotation detection switch generally includes a portion that moves in a first and second direction opposite to each other when coming into contact with the rotatable operation members, and is configured to output a detection signal at each movement. The switch and rotatable operation members are configured so that the movement direction of the detector is in a direction orthogonal to the circumferential direction of rotation.