A power conversion device, which is configured to convert a voltage input from a power source into a desired direct current voltage, the power conversion device comprising: a first switch element and a second switch element, which are connected in series between a positive output terminal and a negative output terminal, wherein the second switch element comprises a semiconductor switching element; a third switch element and a fourth switch element, which are connected in series between the positive output terminal and the negative output terminal at a point closer to the output terminals than the first switch element and the second switch element are, wherein the fourth switch element comprises a semiconductor switching element; a controller, which is configured to control on/off of each of the first switch element, the second switch element, the third switch element, and the fourth switch element; a magnetic coupling reactor including a first winding wire and a second winding wire, which are wound around a shared iron core so as to be magnetically coupled to each other in opposite directions at a turn ratio of 1:1, the first winding wire being connected between a connection point connecting the first switch element to the second switch element and a positive input terminal, the second winding wire being connected between a connection point connecting the third switch element to the fourth switch element and the positive input terminal; and an input capacitor, which is configured to reduce a ripple current, the input capacitor being connected, on a positive side thereof, to the positive input terminal and an input side of the magnetic coupling reactor, the input capacitor being connected, on a negative side thereof, to a negative input terminal and the negative output terminal, wherein the magnetic coupling reactor has a coupling factor equal to or less than 0.8, the power conversion device is characterised in that the first switch element and the third switch element are rectifier diodes and the second switch element and the fourth switch element comprise silicon carbide semiconductor elements. a first switch element and a second switch element, which are connected in series between a positive output terminal and a negative output terminal, wherein the second switch element comprises a semiconductor switching element; a third switch element and a fourth switch element, which are connected in series between the positive output terminal and the negative output terminal at a point closer to the output terminals than the first switch element and the second switch element are, wherein the fourth switch element comprises a semiconductor switching element; a controller, which is configured to control on/off of each of the first switch element, the second switch element, the third switch element, and the fourth switch element; a magnetic coupling reactor including a first winding wire and a second winding wire, which are wound around a shared iron core so as to be magnetically coupled to each other in opposite directions at a turn ratio of 1:1, the first winding wire being connected between a connection point connecting the first switch element to the second switch element and a positive input terminal, the second winding wire being connected between a connection point connecting the third switch element to the fourth switch element and the positive input terminal; and an input capacitor, which is configured to reduce a ripple current, the input capacitor being connected, on a positive side thereof, to the positive input terminal and an input side of the magnetic coupling reactor, the input capacitor being connected, on a negative side thereof, to a negative input terminal and the negative output terminal, wherein the magnetic coupling reactor has a coupling factor equal to or less than 0.8, the power conversion device is characterised in that the first switch element and the third switch element are rectifier diodes and the second switch element and the fourth switch element comprise silicon carbide semiconductor elements.