The Striling engine is the composition of 2 pistons in 2 cylinders or 2 pistons in 1 cylinder except for a double acting type engine. Heater, regenerator and cooler are installed between 2 pistons. In the meantime, the pulse tube engine consists of 1 piston in 1 cylinder, 2^<nd> cooler, pulse tube, heater, regenerator, and cooler. Therefore, the composition resembles the Stirling engine well. So, the engine composition is more simplified, and then, the miniaturization becomes possible. In this paper, in order to improve the performance, the bypass using capillary tube is established during pulse tube and cooler division, and the inertance using capillary tube is installed in 2^<nd> cooler. Effects of the bypass and inertance tube geometries on the engine performance are respectively examined experimentally. As the result, the excellent effects of the bypass and inertance have been confirmed.