NOVELTY - A capacitor module comprises: a set of capacitors; and a laminate electrically connected to the set of capacitors and made up of a first wide conductor and a second wide conductor joined in a layered form with an insulation sheet interposed between the first and second wide conductors.    USE - The capacitor module, power converter, and vehicle-mounted electrical-mechanical system are useful for converting electric power supplied from a vehicle-mounted power supply into motive power (all claimed).    ADVANTAGE - The capacitor module is highly resistant against vibration and has a low inductance.    DETAILED DESCRIPTION - A capacitor module comprises: a set of capacitors; and a laminate electrically connected to the set of capacitors and made up of a first wide conductor and a second wide conductor joined in a layered form with an insulation sheet interposed between the first and second wide conductors, the laminate comprising: a first flat portion including the set of capacitors which are supported thereon and electrically connected to it; a second flat portion being continuous with the first flat portion and extending at a large width in a direction away from the set of capacitors supported on the first flat portion; and connecting portions formed at ends of the first flat portion and the second flat portion and electrically connected to the exterior. INDEPENDENT CLAIMS are:    (1) a power converter electrically connected between a power supply and a load and controlling transfer of electric power between the power supply and the load, the power converter comprising: a power module including a power semiconductor device for switching and electrically connected between the power supply and the load; and a capacitor module electrically connected in parallel to the power supply side of the power module, the capacitor module comprising: a set of capacitors; and a laminate electrically connected to the set of capacitors and made up of a first wide conductor and a second wide conductor-joined in a layered form with an insulation sheet interposed between the first and second wide conductors, the laminate comprising: a first flat portion including the set of capacitors which are supported thereon and electrically connected to it; a second flat portion being continuous with the first flat portion and extending at a large width in a direction away from the set of capacitors supported on the first flat portion; and connecting portions formed at ends of the first flat portion and the second flat portion and electrically connected to the exterior; and    (2) a vehicle-mounted electrical-mechanical system for converting electric power supplied from a vehicle-mounted power supply into motive power, the vehicle-mounted electrical-mechanical system comprising: a motor for generating the electric power; and a power converter electrically connected between the vehicle-mounted power supply and the motor and controlling transfer of electric power between the vehicle-mounted power supply and the motor, the power converter comprising: a power module including a power semiconductor device for switching and electrically connected between the vehicle-mounted power supply and the motor; and a capacitor module electrically connected in parallel to the vehicle-mounted power supply side of the power module, the capacitor module comprising: a set of capacitors; and a laminate electrically connected to the set of capacitors and made up of a first wide conductor and a second wide conductor joined in a layered form with an insulation sheet interposed between the first and second wide conductors, the laminate comprising: a first flat portion including the set of capacitors which are supported thereon and electrically connected to it; a second flat portion being continuous with the first flat portion and extending at a large width in a direction away from the set of capacitors supported on the first flat portion; and connecting portions formed at ends of the first flat portion and the second flat portion and electrically connected to the exterior.