A light emitting element emits a modulated light modulated in a pattern having a repetitive period toward a space. A driving unit drives the light emitting element. A light receiving element distributes charges corresponding to an incident light containing a reflected light obtained by reflecting the modulated light on an object to storage capacitors and stores the distributed charges. A control unit controls an exposure of the light receiving element. A signal processing unit measures a distance to the object by using a value sampled by the light receiving element. The control unit controls the exposure of the light receiving element to give a sensitivity to at least one high-order harmonic. The signal processing unit linearly combines a component of a fundamental wave with a component of the at least one high-order harmonic to measure the distance to the object.