A gas-engine-powered handheld working machine (10) has a working unit driven by a engine capable of running on a gas fuel supplied from a gas cartridge (21). The gas cartridge is arranged such that when the handheld working machine is disposed in a normal rest position where the handheld working machine is placed on a horizontal plane (34) with a bottom surface (14a) of a machine body (14) lying flat on the horizontal plane, the gas cartridge is disposed in a substantially vertical position with a discharge nozzle (23) directed downwards while a central axis (35) of the gas cartridge extends substantially perpendicular to the horizontal plane.
