A matrix converter includes a matrix converter main circuit, an input voltage detector group configured to detect an input voltage of an alternating current source, a gate driver configured to drive a bidirectional switch, and a controller having a pulse width modulation operation unit and a commutation operation unit. The pulse width modulation operation unit is configured to fix one output phase in a conduction state, configured to pulse-width-modulate one of remaining two output phases by using all three input phases, and configured to pulse-width-modulate the other output phase by using only two input phases of a reference input voltage and a middle input voltage.