An output voltage proportional to a duty ratio of a PWM signal can be obtained without using a large-scale circuit, even when a high potential (input potential) of an inverter is low. The digital to analog converter includes a CMOS inverter where a PWM signal generated from a pulse width modulation circuit is inputted, and a low-pass filer supplied with an output of a CMOS inverter. The CMOS inverter includes a P-channel type first MOS transistor and a N-channel type second MOS transistor connected in serial between an input potential and a ground potential, where the PWM signal is applied to each of gates, and an N-channel type third MOS transistor connected with the P-channel type first MOS transistor in parallel and forming a CMOS transmission gate together with the P-channel type first MOS transistor.