An air-cooled engine generator usable in an enclosed and relatively small indoor space includes an engine including a crank shaft on which a generator and a fan are provided. An outside cover includes a discharge aperture which discharges cooling air generated by the fan, and covers the engine, the generator, the fan, and a cooling section. The cooling section includes a mixing chamber where a coolant introduced from the outside and exhaust gas discharged from an exhaust pipe of the engine mix with each other, and an outer circumferential surface which is cooled by the coolant that is introduced into the mixing chamber. The exhaust gas is mixed with and cooled by the coolant in the mixing chamber while the cooling air which is supposed to be discharged out of the air-cooled engine generator is cooled by the outer circumferential surface of the cooling section.