A pulse wave sensor includes: a light emitting unit configured to emit light onto a living body; a light receiving unit configured to receive light transmitted through or reflected from the living body based on the light from the light emitting unit; a pulse wave detecting unit configured to detect a pulse wave of the living body based on a result of light reception by the light receiving unit when the light is emitted from the light emitting unit with a normal light emission intensity; and a light emission intensity adjusting unit configured to cause the light emitting unit to emit light with a predetermined test light emission intensity in a test period prior to the detection of the pulse wave, and set the normal light emission intensity using detection light reception intensity in the light receiving unit by the light emission and a predetermined reference light reception intensity.