Abstract: Disclosed is a boost converter using a stress energy reproducing snubber circuit, the converter comprising a first inductor connected between one terminal of an input portion and a first connection point; a first diode connected between said first connection point and one terminal of an output portion; and a switching device connected between said first connection point and the other terminal of said input portion, the other terminal of said input portion being connected to the other terminal of said output portion, and further comprising a second inductor connected between said first connection point and an anode of said first diode; a capacitor connected between said first connection point and a second connection point; a second diode having an anode connected to said second connection point and a cathode connected to a cathode of said first diode; and a third inductor and a third diode connected in series between said second connection point and the other terminal of said input portion, said third inductor