PROBLEM TO BE SOLVED: To provide a shaft system for a portable working machine operated by hand which is light in weight and highly stable. SOLUTION: In the shaft system for a portable working machine operated by a hand, a lower part connecting unit (18) and an upper part connecting unit (19), a guide tube part (9), and a drive shaft part (10) arranged inside the guide tube part (9) are arranged for combining with adjoining members. The drive shaft part (10) is supported inside the guide tube part (9) through one or more support member (26). The guide tube part (9) is made of carbon fiber reinforced plastic. In one or more regions (49) of the peripheral part of the support member (26) between the support member (26) and the guide tube part (9), a first gap (b) with the magnitude of approximately 15% or less of the inner diameter (a) of the guide tube part (9) is formed. COPYRIGHT: (C)2009,JPO&INPIT
