A power conversion apparatus comprising: a plurality of power conversion units (11-1, 11-2, 11-3, 12-1, 12-2, 12-3) including at least a first power conversion unit (11-1, 11-2, 11-3) having a plurality of semiconductor switching elements and converting AC power into DC power and a second power conversion unit (12-1, 12-2, 12-3) having a plurality of semiconductor switching elements and converting DC power into AC power; a common bus bar extending in a first direction; and a plurality of unit bus bars each constructed of a long conductive plate and extending in a second direction perpendicular to the first direction and provided so as to correspond to the plurality of power conversion units respectively and connecting each DC side of the plurality of power conversion units to the common bus bar; characterized in that each of the power conversion units (11-1, 11-2, 11-3, 12-1, 12-2, 12-3) includes a casing having a first surface on which a first outer plate of a magnetic material is arranged, and the first outer plate is arranged in a vicinity of a corresponding unit bus bar and faces the corresponding unit bus bar with a gap so that an inductance value of the corresponding unit bus bar is increased to an inductance value capable of suppressing an inflow of a ripple current from another power conversion unit in the power conversion apparatus, the casing of each of the plurality of the power conversion units (11-1, 11-2, 11-3, 12-1, 12-2, 12-3) includes a second surface (50B, 50E) adjacent to the common bus bar and perpendicular to the first surface, each of the plurality of the unit bus bars extends along the first outer plate in a direction from the second surface (50B, 50E) of the casing of a corresponding power conversion unit to a third surface (50A, 50F) opposite to the second surface (50B, 50E) of the casing, each distal end portion of the plurality of the unit bus bars has a short bent portion that extends along a portion of the third surface, and each distal end portion is electrically connected to a corresponding power conversion unit via an opening formed on the third surface (50A, 50F), each of the plurality of the unit bus bars includes a positive electrode unit bus bar and a negative electrode unit bus bar arranged in a plane parallel to the first surface of the casing of a corresponding power conversion unit, and the first outer plate is arranged in a vicinity of both of the positive electrode unit bus bar and the negative electrode unit bus bar included in the corresponding unit bus bar, and faces with the gap both of the positive electrode unit bus bar and the negative electrode unit bus bar included in the corresponding unit bus bar. a plurality of power conversion units (11-1, 11-2, 11-3, 12-1, 12-2, 12-3) including at least a first power conversion unit (11-1, 11-2, 11-3) having a plurality of semiconductor switching elements and converting AC power into DC power and a second power conversion unit (12-1, 12-2, 12-3) having a plurality of semiconductor switching elements and converting DC power into AC power; a common bus bar extending in a first direction; and a plurality of unit bus bars each constructed of a long conductive plate and extending in a second direction perpendicular to the first direction and provided so as to correspond to the plurality of power conversion units respectively and connecting each DC side of the plurality of power conversion units to the common bus bar; characterized in that each of the power conversion units (11-1, 11-2, 11-3, 12-1, 12-2, 12-3) includes a casing having a first surface on which a first outer plate of a magnetic material is arranged, and the first outer plate is arranged in a vicinity of a corresponding unit bus bar and faces the corresponding unit bus bar with a gap so that an inductance value of the corresponding unit bus bar is increased to an inductance value capable of suppressing an inflow of a ripple current from another power conversion unit in the power conversion apparatus, the casing of each of the plurality of the power conversion units (11-1, 11-2, 11-3, 12-1, 12-2, 12-3) includes a second surface (50B, 50E) adjacent to the common bus bar and perpendicular to the first surface, each of the plurality of the unit bus bars extends along the first outer plate in a direction from the second surface (50B, 50E) of the casing of a corresponding power conversion unit to a third surface (50A, 50F) opposite to the second surface (50B, 50E) of the casing, each distal end portion of the plurality of the unit bus bars has a short bent portion that extends along a portion of the third surface, and each distal end portion is electrically connected to a corresponding power conversion unit via an opening formed on the third surface (50A, 50F), each of the plurality of the unit bus bars includes a positive electrode unit bus bar and a negative electrode unit bus bar arranged in a plane parallel to the first surface of the casing of a corresponding power conversion unit, and the first outer plate is arranged in a vicinity of both of the positive electrode unit bus bar and the negative electrode unit bus bar included in the corresponding unit bus bar, and faces with the gap both of the positive electrode unit bus bar and the negative electrode unit bus bar included in the corresponding unit bus bar.