To provide a shaft tube of a writing implement which has a tip member having a reduced tightening force and being prevented from easily coming off and has a grip member provided in compression, by a simple structure.

The length of the grip member is made larger than the distance between the step part of a front shaft and the rear end face of the tip member and the grip member is so held as to be compressed between the step part of the front shaft and the rear end face of the tip member, while the outer diameter of the rear end of the grip member is formed to be larger than the outer diameter of the step part of the front shaft and the inner diameter of a rear shaft, and the distance between the end face of the tip member and the fore end face of the rear shaft is made smaller than the length of the grip member. According to this constitution, the grip member is so provided as to be held in the state of being further compressed between the fore end face of the rear shaft and the rear end face of the tip member.