In a multi-channel current steering DA converter, e.g., a two-channel current steering DA converter, reference current sources Irefa and Irefb that can serve as current mirror sources for current sources Ia and Ib are provided in current source matrices 2a and 2b of the channels, respectively. During an operation, the reference current source Irefa or Irefb that is provided in the current source matrix of a channel that is not powered down is selected and used in accordance with control signals 6a and 6b. Therefore, even when one channel is powered down, the full-scale current of the other channel can be maintained at a constant value, i.e., unchanged.