In a current resonance type multi-phase DC/DC converting apparatus for combining, using an output capacitor, M converter output voltages produced by M current resonance type multi-phase DC/DC converters connected in parallel to each other to produce an output voltage, each of the M current resonance type multi-phase DC/DC converters has N current resonance type DC/DC converters connected in parallel with one another. The N current resonance type DC/DC converters have N resonance circuits, respectively. Each of the M current resonance type multi-phase DC/DC converters shares a resonance inductor of the N resonance circuits.