Abstract: An engine generator includes an engine having an intake device and an exhaust device which are connected to an engine body, a generator connected to the engine, and a fuel tank for supplying fuel to the engine. The engine, the generator and the fuel tank are mounted on a frame. In this engine generator, the intake device and the exhaust device are connected to an upper portion of the engine body having a cylinder axis extending vertically to protrude to opposite sides from the engine body, and the fuel tank is disposed sideways of the engine body and the generator below the intake device or the exhaust device. Thus, when a vertical engine is used, the fuel tank can be effectively disposed to avoid the production of a wasteful space, thereby providing reductions in size, weight and cost.