A ΔΣ modulator includes an input circuit having a sampling capacitor, an integration circuit, a quantizer and a D/A converter having a DAC capacitor. The input circuit takes in an analog input voltage in the sampling capacitor in a sampling period, and transfers a charge to the integration circuit in a holding period. The D/A converter takes in an analog potential, to which selection switches are connected in the sampling period based on a digital output of the quantizer, in the DAC capacitor, and subtracts a charge from the integration circuit in the holding period. At this time, since the input circuit and the D/A converter are set so that the holding periods do not overlap with each other, an error caused by the lowering of a feedback factor is suppressed.