a retractable - type writing instrument has a tubular body having a longitudinal axis , a front end , a rear end , and a tip disposed at the front end . a writing medium is disposed in the tubular body for undergoing movement in an axial direction along the longitudinal axis . a clip has a first end portion is connected to the tubular body and a second end portion . an engagement member has a first surface connected to the second end portion of the clip , a second surface confronting the tubular body , and a pair of third surfaces extending from opposite sides of the second surface toward the first surface . each of the third surfaces is inclined at a given angle relative to the longitudinal axis of the tubular body . an operating member is mounted in the tubular body for undergoing movement in the axial direction to move the writing medium between a withdrawal position at which the writing medium is withdrawn into the tubular body and a projected position at which a tip of the writing medium projects from the tip of the tubular body . an engagement body is connected to the operating member for movement therewith and for engaging the engagement member during movement of the operating member in the axial direction to lock the writing medium in the projected position .