To provide a highly efficient DC-DC converter of charge pump type.

The DC-DC converter has an n-channel type MOS transistor and a p-channel type MOS transistor (M2 and M3) for controlling an outflow of a control current (I1), and p-channel type MOS transistors (M1 and M2) for controlling an outflow of a control current (I2). Both ends of a current limiting resistor (R1) are connected to the back gate and drain, respectively, of the p-channel-type MOS transistor (M3), and both ends of a current limiting resistor (R2) are connected to the back gate and drain, respectively, of the p-channel-type MOS transistor (M4).