To provide a small-sized, highly-reliable rotation operation unit.SOLUTION: A rotation operation unit (300) has: a first rotation operation member (400) that is rotationally operable; a first magnet (401) that integrally rotates with the first rotation operation member; a second rotation operation member (500) that is rotationally operable; a second magnet (501) that integrally rotates with the second rotation operation member; and a magnetic sensor (441) that detects magnetism generated by each of the first magnet and the second magnet. The magnetic sensor detects first magnetism in a first direction and a second magnetism in a second direction from the first magnet, and detects third magnetism in a third direction and fourth magnetism in a fourth direction from the second magnet. A first angle made by the first direction and the third direction is larger than a second angle made by the second direction and the fourth direction.SELECTED DRAWING: Figure 11