NOVELTY - The apparatus has a rankine cycle (3a) for circulating working fluid through an boiler and an expander (25) from a pump (P1) such that heat exchange with air-intake system fluid in taken by the boiler cooling with respect to an internal combustion engine (5) and the working fluid is possible. The pump and the expander are connected such that a power transmission is possible. A judgment unit judges cooling required amount with respect to the air-intake system fluid. A control unit severs a connection with an electromagnetic clutch (39) when the required amount exceeds a threshold value.    USE - Waste heat utilizing apparatus for a vehicle.    ADVANTAGE - The control apparatus can judge correctly the cooling required amount with respect to pressurized air based on output requirement with respect to the engine, so that the apparatus can implement improvement of thermal ratio and performance improvement of the engine with respect to pressurized air, thus simplifying a structure of the apparatus. The apparatus allows heat of pressurized air to be moved to the working fluid and temperature of pressurized air to be lowered, so that supply of pressurized air is attained with respect to the engine, thus improving an output of the engine and making rotational driving force obtained by pressure energy of the working fluid pressure-reduced in the expander to be revived by the engine.    DETAILED DESCRIPTION - The boiler is a recirculation exhaust boiler or pressurized air boiler (23). The internal combustion engine is a well-known water cooling type petrol engine. The judgment unit and the control unit function as a control apparatus (11a). The electromagnetic clutch is a multi-panel-type clutch.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a waste heat utilizing apparatus.    Pump (P1)    Drive system (1a)    Rankine cycle (3a)    Internal combustion engine (5)    Control apparatus (11a)    Pressurized air boiler (23)    Expander (25)    Electromagnetic clutch (39)