To detect whether the pulse detector is in an unworn state, the pulse detector is provided for detecting a pulse signal that originates in the pulse of a subject has a pulse wave sensor, a pulse wave sensor sensitivity adjustment section that adjusts the sensitivity of the pulse wave sensor, a body movement sensor, and an unworn-state detector that detects that the pulse detector has been removed from the subject and is in an unworn state, on the basis of the sensitivity of the pulse wave sensor sensitivity adjustment section and a body movement sensor signal outputted from the body movement sensor.