An electric drive system comprising a power control unit for converting direct-current power to alternating-current power and supplying the converted power to an electric motor for driving a vehicle, and an onboard device case inside which the power control unit is fixed, the power control unit comprising: a step-down converter configured to step down voltage of the direct-current power; and a step-up converter configured to step up voltage of the direct-current power, the step-up converter including a reactor (38, 116) and a capacitor (40, 136), the reactor (38, 116) and the step-down converter being fixed to the onboard device case (62, 130), and the reactor (38, 116) and the step-down converter being stacked, the capacitor (40, 136) being affixed to the onboard device case and arranged next to at least one of the reactor (38, 116) or the step-down converter, with respect to a direction in which the reactor (38, 116) and the step-down converter are stacked, and the capacitor (40, 136) and at least one of the step-down converter or the reactor (38, 116) being fixed together by a bus bar (98, 104, 110), the bus bar (98, 104, 110) being configured to electrically connect a terminal (74, 82, 78, 86, 100, 102) of the capacitor (40, 136) to a terminal (74, 82, 78, 86, 100, 102) of at least one of the step-down converter or the reactor (38, 116), wherein the capacitor (40, 136) is fixed to the onboard device case (62, 130) at fixing points (88, 88) in two locations; and the bus bar (98, 104, 110) fixes the capacitor (40, 136) to at least one of the step-down converter or the reactor (38, 116) at a position away from a straight line that passes through the fixing points (88, 88) in two locations in a stacking direction. the power control unit being characterized in that the bus bar (98, 104, 110) is a linear, flat plate-like conductor plate that extends in a direction that orthogonally intersects a direction in which the straight line that passes through the fixing points(88, 88) in two locations of the capacitor (40, 136) extends. a step-down converter configured to step down voltage of the direct-current power; and a step-up converter configured to step up voltage of the direct-current power, the step-up converter including a reactor (38, 116) and a capacitor (40, 136), the reactor (38, 116) and the step-down converter being fixed to the onboard device case (62, 130), and the reactor (38, 116) and the step-down converter being stacked, the capacitor (40, 136) being affixed to the onboard device case and arranged next to at least one of the reactor (38, 116) or the step-down converter, with respect to a direction in which the reactor (38, 116) and the step-down converter are stacked, and the capacitor (40, 136) and at least one of the step-down converter or the reactor (38, 116) being fixed together by a bus bar (98, 104, 110), the bus bar (98, 104, 110) being configured to electrically connect a terminal (74, 82, 78, 86, 100, 102) of the capacitor (40, 136) to a terminal (74, 82, 78, 86, 100, 102) of at least one of the step-down converter or the reactor (38, 116), wherein the capacitor (40, 136) is fixed to the onboard device case (62, 130) at fixing points (88, 88) in two locations; and the bus bar (98, 104, 110) fixes the capacitor (40, 136) to at least one of the step-down converter or the reactor (38, 116) at a position away from a straight line that passes through the fixing points (88, 88) in two locations in a stacking direction. the power control unit being characterized in that the bus bar (98, 104, 110) is a linear, flat plate-like conductor plate that extends in a direction that orthogonally intersects a direction in which the straight line that passes through the fixing points(88, 88) in two locations of the capacitor (40, 136) extends.