The invention relates to a bidirectional DC-DC converter with intermediate conversion into AC power, including: a DC-AC conversion circuit using a plurality of MOSFETs; an AC-DC conversion circuit using a plurality of power diodes; a transformer; a pair of switches, one of which being inserted in series between a DC terminal of the DC-AC conversion circuit and the AC-DC conversion circuit and the other of which being inserted in series between another DC terminal of the DC-AC conversion circuit and the AC-DC conversion circuit; and a controller being adapted for turning on the pair of switches such that the plurality of power diodes of the AC-DC conversion circuit are reverse-biased where the AC power is transferred in the forward direction and turning off the pair of switches where the AC power is transferred in the backward direction.