DC/DC power-converting device

Possess: reactor (L), is connected with DC power supply; DC voltage conversion portion (A), be connected with reactor (L), have multiple switch element (S1), (S2), by this switch element (S1), the ON/OFF of (S2) and the charge and discharge capacitance device (Cf) of discharge and recharge and the multiple diodes (D1), (D2) that provide the charge path of charge and discharge capacitance device (Cf) and discharge path; The smmothing capacitor (Co) of outlet side, is connected with DC voltage conversion portion (A), have mutually be connected in series multiple voltage-dividing capacitors (Co1), (Co2); And the switch element of voltage equalization (Df), be arranged in the connecting line arranged between the mutual tie point of the negative side terminal of charge and discharge capacitance device (Cf) and each voltage-dividing capacitor (Co1), (Co2).