An A/D conversion apparatus performs motor current detection in an A/D conversion period corresponding to two phases out of three phases of a sinusoidal drive motor, using reduced register resources while minimizing the number of A/D converters. The A/D conversion apparatus includes: a selection unit selecting one of a plurality of input channels; an A/D converter converting an analog signal from the selected input channel to a digital signal; a start register holding a start channel number of sequential conversion; an end register holding an end channel number of the sequential conversion; a prohibition information holding unit holding prohibition information indicating an input channel to be excluded from the sequential conversion; and a control unit causing the selection unit to select, in channel number order, input channels corresponding to channel numbers from the start channel number to the end channel number except the input channel indicated by the prohibition information.