a combustion type power tool capable of restraining reduction in output power due to lowering of combustion efficiency . a specific space within a combustion - chamber frame is enlarged . the specific space contains a specific region where high turbulence occurs in a combustion chamber at which a fuel is ignited . the enlargement is made by providing an enlarged distance between a rotation shaft of the fan and an inner wall of the combustion - chamber frame . when the turbulent combustion occurring at the specific region is expanded in the combustion chamber , flame propagation contour of the turbulent combustion reaches the wall of the combustion - chamber frame and ribs at a delayed timing . therefore , after the turbulent combustion is sufficiently promoted , the flame reaches the combustion - chamber frame and the ribs . in other words , the flame does not reach the combustion - chamber frame and the ribs at the initial stage of turbulent combustion . thus , combustion heat at the initial stage of turbulent combustion is not robbed , but the combustion is promoted . efficient power generation from the fuel is achievable without lowering combustion efficiency .