A power generating apparatus has a simplified structure for introducing fuel vapor from a fuel tank and blow-by gas produced in an engine into the engine's intake system so as to facilitate the manufacturing of the power generating apparatus. The power generating apparatus includes an engine for driving a generator, a canister containing an adsorbent for adsorbing thereonto fuel that evaporates from a fuel tank, an evaporative fuel inlet pipe for introducing fuel vapor purged from the adsorbent into an engine intake system, and a blow-by gas inlet pipe for introducing blow-by gas produced in the engine into the intake system. A first end of the evaporative fuel inlet pipe is connected to the canister, and a second end of the evaporative fuel inlet pipe is connected to an intermediate portion of the blow-by gas inlet pipe.