In the present invention, a package is partitioned into upper and lower sections. An engine and a generator are both disposed in the lower section. In the upper section are disposed: a radiator chamber in which a radiator and a radiator fan are disposed, and an intake chamber in which an intake silencer is disposed. A ventilation hole directly communicates the radiator chamber with an engine chamber in which the engine and the generator are disposed. The ventilation hole is displaced from the radiator fan in a long-side direction of the package. A ventilation hood covers above and around the ventilation hole. An outlet opening of the ventilation hood is formed being displaced in a short-side direction (Y) of the package to face the ventilation hole.