A combustion type power tool capable of avoiding wasteful injection of combustible gas from a gas canister even if an unintentional operation of the push lever takes place, and capable of avoiding wasteful electric power consumption even if a battery used as power supply remains set in the tool. While the tool is not being used, a stop unit is set at a stop position, preventing a gas canister from injecting gas, and while the tool is being used, the stop unit is set at a release position, allowing the gas canister to inject gas as a result of movement of a combustion chamber frame.