A variable resistor array adapted to make a resistance value between a first terminal and a second terminal variable, includes a plurality of resistors connected in series, first through nth MOS transistors selectively connected to the resistors, and first through nth switches having one input terminal connected to the source of the ith MOS transistor, another input terminal connected to a predetermined voltage, and an output terminal connected to a back gate of the ith MOS transistor, and connecting either one of the one input terminal and the other input terminal to the output terminal under control of the ith control signal. The ith switch connects the other input terminal to the output terminal, and the ith switch also connects the one input terminal to the output terminal.