A rotary sensing device that can accurately detect a rotation direction, even if a rotating body rotates at a high speed, when a gap between a plurality of subjects for detection in a rotating body varies is equipped with first to Nth sensor elements that are aligned to oppose the rotating body, which is rotatable in a rotation direction that can be either a normal rotation direction or a reverse rotation direction, and in parallel in respective order along the rotation direction, and that output first to Nth (N>=3) sensor signals based upon the rotation of the rotating body, respectively, and a rotation direction detecting part that detects the rotation direction of the rotating body based upon each sensor signal output from each sensor element, and the rotation direction detecting part detects the rotation direction of the rotating body from a first differential signal that is obtained from the first sensor signal and the Mth (3<=M<=N) sensor signal, and a second differential signal obtained from the first sensor signal and the Lth (2<=L<=M-1) sensor signal.