[Problem] To provide a pulse sensor capable of accurately measuring the pulse of a subject. [Solution] A pulse sensor (600) has: a housing (610) mounted to an external ear an optical sensor unit (620) which is disposed upon the housing (610) and acquires pulse data by emitting light from a light-emitting portion onto the external ear and detecting, at a light-receiving unit, the intensity of the light that is transmitted through a living body and returns and a buffer member (630) which is disposed between the housing (610) and the optical sensor unit (620).