An electronic still camera has first and second gain controller circuits and a gain storage memory. The gain storage memory includes a first gain table for storing gains for an R amplifier and a B amplifier of the first gain controller circuit; and a second gain table for storing gains for an R amplifier and a B amplifier of the second gain controller circuit, during auto white balance control using light emission of a strobe. The gains of the second gain table are sequentially set to the second gain controller circuit to carry out white detection. Based on a result of the detection, a gain to be set to the first gain controller circuit is selected from the first gain table, and the selected gain is set to the first gain controller circuit.