Abstract: An engine generator system in which an exhaust muffler mounted on a frame in an engine area is disposed above a portion of a generator with an upper portion of a heat shield plate interposed between the muffler and a fuel tank. A battery is mounted on a battery base and disposed in the engine area with a heat shield plate 26 interposed between the battery and a control box. A battery cover partitions off the battery and the muffler from each other is fastened to the heat shield plate and the battery base at a location displaced sideways from the battery. Harnesses pass through grommets mounted on the battery cover, individually corresponding to plus and minus terminals. Thus, the battery can be mounted on the frame while preventing an increase in size of the system and to prevent the wiring from being complicated. Moreover, an adverse effect to the battery due to heat from the muffler can be prevented.