Packaged engine working machine

There is provided a packaged engine working machine including, in a lower space of a package in which an engine is disposed, an electrical component storage box adapted so to be impervious to heat from the engine and intrusion of dust or the like. In a packaged engine working machine 1 in which an engine 5 and a working machine 6 driven by the engine are disposed in a lower space 4 of a package 2, a storage box 50 for storing a non-heat-generating electrical component 53 included in electrical components for the engine and working machine, and a ventilation duct 70 having a ventilation fan 7 for sucking outside air A into the lower space are each disposed in the lower space, and the packaged engine working machine includes an introduction path P through which the ventilation duct and the storage box are communicated with each other, and the outside air sucked by the ventilation fan is partially guided into the storage box.