A power converter, comprising: a mounting substrate (14, 28) mounted with a power converting circuit for converting electric power supplied from a power supply and supplying the converted electric power to a load; a one-piece-type connector including an input connector by which an input cable for inputting the electric power supplied from the power supply to the power converting circuit is connected to the mounting substrate (14, 28) and an output connector by which an output cable for outputting the converted electric power to the load is connected to the mounting substrate (14, 28), the input connector and the output connector being formed in one-piece and arranged side by side; and a case made of an electrically conductive material and configured to accommodate the mounting substrate (14, 28) and the one-piece-type connector, wherein the one-piece-type connector includes lead terminals (23a-23g, 27a-27g) configured to connect the input cable and the output cable to the power converting circuit and an electrically conductive ground connection portion (21, 26) electrically connected to the case through an electrically conductive member, the ground connection portion including a shield surface arranged to extend along at least a portion of a side surface of the output connector, wherein the one-piece-type connector further includes a connecting portion to interconnect the input connector and the output connector, the ground connection portion (21, 26) including a base portion installed on the connecting portion and an upstanding portion extending along a portion of a side surface of the output connector, wherein the electrically conductive member includes a screw extending through the base portion and the mounting substrate (14, 28) to fix the ground connection portion (21, 26) to the case, and wherein the ground connection portion (21, 26) further includes leg portions (21d, 21e, 26a, 26b) extending from the base portion so as to make contact with the mounting substrate (14, 28), each of the leg portions (21d, 21e, 26a, 26b) including a bent portion (21h, 21i) flexed depending on a difference in an attachment height of the lead terminals (23a-23g, 27a-27g) with respect to the mounting substrate (14, 28) characterized in that the mounting substrate (14, 28) has through-holes (14c, 14d) formed at adjacent positions with a mounting position of the connecting portion of the one-piece-type connector interposed therebetween, the leg portions (26a, 26b) being inserted into the through-holes (14c, 14d) and being configured to fix the one-piece-type connector at a predetermined height by being locked to the through-holes (14c, 14d) in a state that the base portion is mounted to the connecting portion. a mounting substrate (14, 28) mounted with a power converting circuit for converting electric power supplied from a power supply and supplying the converted electric power to a load; a one-piece-type connector including an input connector by which an input cable for inputting the electric power supplied from the power supply to the power converting circuit is connected to the mounting substrate (14, 28) and an output connector by which an output cable for outputting the converted electric power to the load is connected to the mounting substrate (14, 28), the input connector and the output connector being formed in one-piece and arranged side by side; and a case made of an electrically conductive material and configured to accommodate the mounting substrate (14, 28) and the one-piece-type connector, wherein the one-piece-type connector includes lead terminals (23a-23g, 27a-27g) configured to connect the input cable and the output cable to the power converting circuit and an electrically conductive ground connection portion (21, 26) electrically connected to the case through an electrically conductive member, the ground connection portion including a shield surface arranged to extend along at least a portion of a side surface of the output connector, wherein the one-piece-type connector further includes a connecting portion to interconnect the input connector and the output connector, the ground connection portion (21, 26) including a base portion installed on the connecting portion and an upstanding portion extending along a portion of a side surface of the output connector, wherein the electrically conductive member includes a screw extending through the base portion and the mounting substrate (14, 28) to fix the ground connection portion (21, 26) to the case, and wherein the ground connection portion (21, 26) further includes leg portions (21d, 21e, 26a, 26b) extending from the base portion so as to make contact with the mounting substrate (14, 28), each of the leg portions (21d, 21e, 26a, 26b) including a bent portion (21h, 21i) flexed depending on a difference in an attachment height of the lead terminals (23a-23g, 27a-27g) with respect to the mounting substrate (14, 28) characterized in that the mounting substrate (14, 28) has through-holes (14c, 14d) formed at adjacent positions with a mounting position of the connecting portion of the one-piece-type connector interposed therebetween, the leg portions (26a, 26b) being inserted into the through-holes (14c, 14d) and being configured to fix the one-piece-type connector at a predetermined height by being locked to the through-holes (14c, 14d) in a state that the base portion is mounted to the connecting portion.