Disclosed is a bidirectional DC/DC converter including: a primary side circuit that includes a first DC power source or a first load; a secondary side circuit that includes a second load or a second DC power source; and a power transfer unit that is capable of transferring power bi-directionally between the primary side circuit and the secondary side circuit. Further, the bidirectional DC/DC converter includes a control circuit that controls the primary side circuit and secondary side circuit in such a way that current flows through the power transfer unit from the first DC power source to the second load or from the second DC power source to the first load.