MULTI-TIP WRITING INSTRUMENT

PROBLEM TO BE SOLVED: To provide a multi-tip writing instrument preventing erroneous release between a refill and a knock member to allow stable writing with a simple structure.SOLUTION: The multi-tip writing instrument includes: a barrel 12 having a central axial line X; a refill 21; and a knock member 18 movable from a rear end position to a front end position entering a radial direction inner side perpendicular to the central axial line after being slid and moved toward a front end of the barrel parallel to the central axial line X. The knock member includes: a slider body 28; a mounting part 22 extending forward from the front end of the slider body and inserted into a rear end of the refill; an engagement protruding part 40 protruding in a direction perpendicular to the central axial line in a side surface of the mounting part, engaged with a rear end inner circumferential surface of the refill when the refill is inserted, and allowing the slider body to be swingable in a radial direction perpendicular to the central axial line relative to the refill; and a first regulation surface 28a formed at the front end of the slider body and abutting against a rear end surface of the refill to regulate the swing of the slider body at a radial direction outer side perpendicular to the central axial line.