A power converter comprising: a power converter circuit configured to convert input electric power into DC power or AC power; a cooler on which the power converter circuit is placed to cool the power converter; and a cover member that houses the power converter circuit between the cooler and the cover member, wherein the cooler includes: a main body; a coolant flow passage formed inside the main body, a coolant being circulatable through the coolant flow passage; and a coolant input/output portion coupled to the coolant flow passage, the coolant input/output portion including a coolant introduction pipe and a coolant discharge pipe, the coolant introduction pipe introducing the coolant from outside the cooler, the coolant discharge pipe discharging the coolant to outside the cooler, characterized in that the coolant input/output portion is joined to a lower surface of the main body such that at least distal end portions of the coolant introduction pipe and the coolant discharge pipe project outside with respect to a side surface of the main body in a surface direction thereof, wherein a joined part between the coolant input/output portion and the main body has a joining strength lower than a strength of the main body such that upon application of an external force during a collision or the like, which acts on the input/output portion, the joining of the coolant input/output portion to the lower surface of the main body is released against this external force before the main body is damaged, and the power converter circuit is placed on an upper surface of the main body. a power converter circuit configured to convert input electric power into DC power or AC power; a cooler on which the power converter circuit is placed to cool the power converter; and a cover member that houses the power converter circuit between the cooler and the cover member, wherein the cooler includes: a main body; a coolant flow passage formed inside the main body, a coolant being circulatable through the coolant flow passage; and a coolant input/output portion coupled to the coolant flow passage, the coolant input/output portion including a coolant introduction pipe and a coolant discharge pipe, the coolant introduction pipe introducing the coolant from outside the cooler, the coolant discharge pipe discharging the coolant to outside the cooler, characterized in that the coolant input/output portion is joined to a lower surface of the main body such that at least distal end portions of the coolant introduction pipe and the coolant discharge pipe project outside with respect to a side surface of the main body in a surface direction thereof, wherein a joined part between the coolant input/output portion and the main body has a joining strength lower than a strength of the main body such that upon application of an external force during a collision or the like, which acts on the input/output portion, the joining of the coolant input/output portion to the lower surface of the main body is released against this external force before the main body is damaged, and the power converter circuit is placed on an upper surface of the main body. a main body; a coolant flow passage formed inside the main body, a coolant being circulatable through the coolant flow passage; and a coolant input/output portion coupled to the coolant flow passage, the coolant input/output portion including a coolant introduction pipe and a coolant discharge pipe, the coolant introduction pipe introducing the coolant from outside the cooler, the coolant discharge pipe discharging the coolant to outside the cooler, characterized in that the coolant input/output portion is joined to a lower surface of the main body such that at least distal end portions of the coolant introduction pipe and the coolant discharge pipe project outside with respect to a side surface of the main body in a surface direction thereof, wherein a joined part between the coolant input/output portion and the main body has a joining strength lower than a strength of the main body such that upon application of an external force during a collision or the like, which acts on the input/output portion, the joining of the coolant input/output portion to the lower surface of the main body is released against this external force before the main body is damaged, and the power converter circuit is placed on an upper surface of the main body.