We have developed double acting type (DA type) six cylinder Stirling engine. In the engine our developing, it is thought that the increase and decrease of the frictional force and the working mixture leakage greatly influences at the temperature around the piston ring because of the difference of Coefficient of thermal expansion of both with the endless type piston ring made of polytetrafluoethylene though the cylinder of a stainless steel-made is used. The piston ring that can correspond to the thermal expansion by putting the multistep type step cutting in the endless type piston ring used to improve this problem so far is developed. On the other hand, it reports on output data that the performance of the endless type piston ring and the piston ring by the multistep type step cutting was able to be measured.