A power module includes an upper arm circuit unit and a lower arm circuit unit each having a power semiconductor element; an insulating substrate with the units mounted on one surface thereof; a metal base bonded onto the other surface of the substrate opposite to the one surface where the units are mounted; a first connection conductor for supplying a high potential to the upper unit from outside; a second connection conductor for supplying a low potential to the lower unit from outside; an insulating sheet interposed between the conductors; and a resin case disposed on the metal base to support the conductors, the conductors are flat conductors and laminated with the sheet sandwiched therebetween; the sheet extends from one end of the laminated structure to secure the creepage distance between the conductors; and the case is furnished with a recess for containing the laminated structure.