A turbocharger system for simultaneously improving a fuel efficiency and obtaining a satisfactory hill start performance due to a downsized engine. The system includes an electric assist turbocharger which includes a turbine disposed in an exhaust passage of an engine and driven by exhaust gas, a compressor disposed in an intake passage and driven by a rotational torque of the turbine, and an electric motor assisting a driving force of the compressor and an electric motor control unit which drives the electric motor when detecting a start operation at a sloping road.