To aim at reducing the switching loss of an inverter in PWM control, and also harmonic currents in a control method of a compressor.

When an AC power source is converted into DC voltage in a rectifier, the DC voltage is set to a predetermined DC voltage by an active filter and supplied to the inverter, an arbitrary AC voltage generated by the inverter is applied to operate a motor, a switching means of the active filter is driven as predetermined so that an input AC wave form (see Fig. 1 (a)) is a sinusoidal wave form, and PWM control and PAM control are carried out to drive the motor. When the motor is stopped or is in PWM control, the output DC voltage of the active filter is detected, the set output voltage of the active filter is made a lower by the predetermined amount than the detection output DC voltage, and at least the switching means of the active filter is stopped near the peak of the input AC current wave form (see figure 1 (b)).