PROBLEM TO BE SOLVED: To solve a problem of shock generated when a portable working machine is put on the ground and thereby to absorb the shock when the machine is put on the ground. SOLUTION: In the portable working machine, a reduction mechanism 44 reduces a revolution speed of an engine 12, and a motion conversion mechanism 45 converts the revolution with reduced speed into a linear reciprocating motion to drive a cutting blade 13, 14 and thereby to cut the branches and leaves. The motion conversion mechanism 45 and reduction mechanism 44 are housed in the case 31, and the engine 12 is attached to a portion facing the reduction mechanism 44 and on an upper surface of the case 31. A cover member 23 is disposed to a lower surface 31a of the case 31, is connected with the lower surface 31a of the case 31 at a potion approximately facing the motion conversion mechanism 45, and is extended in a cantilever beam fashion. A space S is formed between the portion facing the reduction mechanism 44 and the lower surface 31a of the case 31, and an impact-absorbing member 41 is disposed in the space S. COPYRIGHT: (C)2005,JPO&NCIPI