ROTATION ANGLE SENSOR

PROBLEM TO BE SOLVED: To provide a rotation angle sensor capable of stably obtaining a highly accurate detection result.SOLUTION: In a rotation angle sensor 1, the rotation angle of a rotor 5 housed in a housing 2 is detected by the detection part of the housing 2. A peripheral wall part 25 extends from a housing chamber 24 having the housing 2 which houses the rotor 5. A partition wall 3 is provided in the inner peripheral surface of the peripheral wall part 25. The partition wall 3 includes: a partition part 31 extending along the rotating direction of the rotor 5; a movement control part 33 arranged in one end side of the partition part 31; and a receiving part 32 arranged between the partition part 31 and the movement control part 33. The rotor 5 includes a pair of control members 52 and 54 arranged so as to have a gap between the control means 52 and 54 and the partition part 31 and to sandwich the partition part 31, and is mounted on a throttle shaft S and is rotated integrally with the throttle shaft S.