To provide an inversion-type DC/DC converter that controls its output voltage regardless of effect of disturbance, etc. of a power voltage.

A converter controller 10 has an error amplifier 3, in which a reference voltage is input into its inverting input terminal and a feedback voltage being converted into a positive voltage by a circuit 1 for conversion into a positive voltage is input into its non-reverse input terminal, and a pulse width modulation comparator 4, in which the output of the error amplifier 3 is input into its inverting input terminal and a sawtooth oscillation signal is input into its non-reverse input terminal. The circuit 1 for conversion into a positive voltage includes a first N-channel MOS transistor of current mirror structure, a second N-channel MOS transistor, a first P-channel MOS transistor, and a second P-channel MOS transistor, and the drain voltage of the second N-channel transistor (NchTr2) is input into the error amplifier as a voltage where the feedback voltage is converted into a positive voltage.