To eliminate stain of suit or shirt even if a writing implement is inserted into a pocket in the state that a writing tip remains projected by bringing a step for unlocking provided at a locking pin into contact with a rear end of a knocking member to release a locking state of the member, and retracting the tip from a tip port.

When a clip 6 is inserted into a pocket in the state that a writing tip is projected from a tip port of a front barrel, an end of the clip 9 is movable in a direction for separating it from a rear barrel side. A cam 9c of a leg presses to move forward a cam face 6a of a locking pin 6 in cooperation with the movement of the clip 9. And, an oblique step 7 is brought into contact with a protrusion 28 of a knocking member 26 to release the locking state of the rear end to the end 20 of a barrel front end, and the writing tip is retracted in the front barrel 25 from the tip port. Accordingly, there is no anxiety that the suit or shirt is contaminated with the writing tip.