An exhaust gas temperature raising processing system, which increases a load acting on an engine to raise the exhaust gas temperature, includes an electric assist motor connected to the engine and an inverter for adjusting a torque of the electric assist motor. It also includes a main controller having a first determination unit for determining whether or not an actuator control valve is in a non-feed state and a second determination unit for determining whether or not clogging has occurred on a filter of an exhaust gas purification system. When the non-feed state is determined by the first determination unit and clogging is determined to have occurred on the filter by the second determination unit, the main controller drives the electric assist motor to generate electric power such that a load acting on the engine is increased.