To provide an oscillator capable of achieving a clock signal with a constant duty ratio by generating a voltage toggled using a voltage having no relation with a temperature from a band gap circuit in charging and discharging a capacitor.

The oscillator includes: a band gap circuit that provides a band gap reference voltage with a predetermined voltage level; a voltage-current conversion section that converts the band gap reference voltage from the band gap circuit into an electric current; a charge and discharge section that provides a triangular wave signal by charging and discharging the converted current; and a T flip-flop that provides a clock signal with a duty fixed by logically computing the triangular wave signal from the charge and discharge section.