To provide a low-ripple power supply capable of not increasing a current ripple of individual voltage reversible chopper and capable of reducing the whole current ripple.

This low-ripple power supply is constituted of a voltage reversible chopper N (N is a positive odd number) set which has a positive side step-down chopper 31 connected to a common DC power supply 1 and for supplying a positive DC to a common load 7 through a positive side coupling reactor, and a negative side step-down chopper 41 connected to the DC power supply 1 and for supplying a negative DC to the load 7 through a negative side coupling reactor. A phase difference between a carrier wave for pulse width-controlling a switching element of the positive side step-down chopper of the respective voltage reversible choppers and the carrier wave for pulse width-controlling the switching element of the negative side step-down chopper is defined as π. The phase of the carrier wave of the switching elements of the positive side step-down chopper of the voltage reversible chopper N set, and the phase of the carrier wave of the switching elements of the negative side step-down chopper are uniformly shifted by 2π/N.