Semiconductor device and electronic control unit using the same

A semiconductor device with enhanced heat releasability and low-cost manufacturability is disclosed. This device has a substrate (1) with an electronic circuit disposed on a first principal surface, a semiconductor element (6) which is provided at the first surface of the substrate and electrically connected by wire bonding (2) to the electronic circuit, a metallic core layer (1a) which is provided in the substrate (1) and electrically connected to the semiconductor element (6), a plurality of conductive bumps (7) provided on a second principal surface opposite to the first surface of the substrate (1), a thermal hardenable sealing resin (5) for sealing at least the semiconductor element (6) and the first surface side of the substrate (1), and a metal plate (8) provided at the second surface for being electrically connected to the metal core layer (la). An electronic control module using the device is also disclosed.