The analog-to-digital converter includes a quantizer for outputting a quantized signal, a sampling circuit for sampling an analog input signal, a dithering circuit for generating an added voltage, and an integrating circuit for integrating a signal on which the added voltage is superimposed and outputting an integration result to the quantizer. The dithering circuit includes a variable capacitance circuit and a control circuit. The variable capacitance circuit includes a plurality of capacitors. The control circuit controls the capacitance of the variable capacitance circuit to a capacitance smaller than the capacitances of the capacitors, and causes the variable capacitance circuit to generate an added voltage.