Engine waste heat recovering apparatus

A means for eliminating a frozen or near frozen state in a drain of the condensed water generated by the action of an exhaust gas heat exchanger (9) is provided. The condensed water separated from the exhaust gas in a silencer (31) is passed through a waster water trap provided with the joint (34) and discharged to the outside. The joint (34) also has a passage provided therein for circulating a heat transfer medium through an externally (separately) installed heat exchanger (52A). When the engine (2) is started, it is judged based on the temperature of the waster water trap (36), (37) or the water measured by a sensor (53) whether the frozen state is present or not. When it is judged that the frozen state is present, a water pump (10) is switched on for circulating the heat transfer medium through the waster water trap (36), (37).