To provide an oscillator with its power consumption reduced and a method for controlling its operating current.

An oscillator comprises: charge and discharge sections M11-M14 that switch charging/discharging of capacitors C51 and C12 according to a control signal; comparators 53 and 13 that output a comparison result signal by comparing a capacitor voltage with a reference voltage; a flip-flop 61 that is set or reset by the comparison result signal, and supplies an output signal to the charge and discharge section as a control signal as well as outputting it as an oscillation signal; current control sections 16-19 that control the operating current of the comparator according to the capacitor voltages.