To provide an engine working machine in which startability is improved by employing a low-voltage battery.

The machine includes a battery 80, a booster (130) which raises a voltage supplied from the battery 80, a temperature detection means (119) for detecting a temperature, and a solenoid valve 104 for additionally injecting fuel in a cylinder of an engine 10. When the temperature detected by the temperature detection means (119) is not higher than a prescribed value, the solenoid valve 104 is driven by the voltage boosted by the booster (130) to additionally inject fuel in the cylinder. The action of the solenoid valve 104 is executed by a control means having a microcomputer 118.