A pulse wave sensor includes: an optical sensor unit configured to irradiate a living body with light emitted from a light emitting unit and detect light reflected from or transmitted through the living body with a light receiving unit to generate a current signal in accordance with a light reception intensity a pulse driving unit configured to turn on or turn off the light emitting unit at a predetermined frame frequency and a predetermined duty rate a current-voltage conversion circuit configured to convert the current signal into a voltage signal and a detection circuit configured to extract an upper envelope and a lower envelope of the voltage signal and obtain a difference therebetween to generate a detection signal.
