TECHNOLOGY FOCUS - ELECTRONICS - Preferred Module: In the capacitor module, the first flat portion is resin-molded together with the set of capacitors, and the second flat portion is exposed from the molded resin and is extended at a large width in a direction away from the molded resin. The bent portion is formed midway the second flat portion. The set of raised lugs is formed in each of the first wide conductor and the second wide conductor, each of the set of capacitors has electrodes formed at opposite end surfaces, and the electrode at one end surface is electrically connected to corresponding one of the raised lugs formed in the first wide conductor, and the electrode at the other end surface is electrically connected to corresponding one of the raised lugs formed in the second wide conductor. The electrodes of at least one of the set of capacitors are arranged in direction reversal to a direction in which the electrodes of the other capacitors are arranged. The set of capacitors have positive electrodes at ones of opposite end surfaces and negative electrodes at the other end surfaces and are arrayed on the first flat portion such that electrode directions from the positive electrodes to the negative electrodes are substantially parallel to each other, and the electrode directions of adjacent capacitors are reversal to each other. The capacitor module is mounted in surface contact to a housing a part of which is cooled by a coolant. Preferred Converter: In the power converter, the first flat portion is resin-molded together with the set of capacitors, and the second flat portion is exposed from the molded resin and is extended at a large width in a direction for connection to the power module. The power module has connecting portions to which is connected the capacitor module, and those ones among the connecting portions of the capacitor module which are connected to the power module are directly connected to the connecting portions of the power module. The connecting portions of the capacitor module which are connected to the power module are formed by being bent with respect to the second flat portion, the power module has connecting portions to which is connected the capacitor module, the connecting portions of the power module are bent midway, and the capacitor module and the power module are electrically connected to each other such that a direction in which those ones among the connecting portions of the capacitor module which are connected to the power module are bent and extended is made the same as a direction in which the connecting portions of the power module are bent and extended, and that the bent connecting portions of the capacitor module and the power module are fixed to each other in an abutted state. The power converter includes the power module and the capacitor module in two pairs, a power-module connecting portion of a first capacitor module and a power-module connecting portion of a second capacitor module are connected to a capacitor- module connecting portion of a first power module and a capacitor-module connecting portion of a second power module by jointly fastening the corresponding connecting portions together, and the first and second power modules and the first and second capacitor module are connected in parallel to each other in the connecting portions. Preferred System: In the vehicle-mounted electrical-mechanical system, the first flat portion is resin-molded together with the set of capacitors, and the second flat portion is exposed from the molded resin and is extended at a large width in a direction for connection to the power module. The bent portion is formed midway the second flat portion.