To provide a DC power-supply device that can suppress voltage unbalance of a plurality of capacitors serially connected between both terminals of a load, achieve stable drive of the load and long life of the capacitors, and contribute to high reliability, in a configuration in which an alternating current is converted into a direct current and is supplied to a load, and a refrigeration-cycle application device including the DC power-supply device. The DC power-supply device includes a rectifier circuit, a reactor connected to an input or an output side of the rectifier circuit, a first capacitor and a second capacitor serially connected between output terminals to a load, a charging unit that selectively charges one or both of the first capacitor and the second capacitor, and further includes a control unit that controls the charging unit so that voltage unbalance between the first capacitor and the second capacitor is suppressed.