A writing implement is provided including a knock mechanism, in which, without obstruction of normal operation, impact can be cushioned by a damper space that is sealed off from the outside. The writing implement (10) including the knock mechanism capable of advancing a writing tip (11) by push-out operation, includes: a holding section (12) for holding the writing tip (11); a shaft tube (20) for containing the holding section (12); a knock section (30) for covering a rear end portion of the shaft tube (20); a push-out section (13) for pressing the holding section (12) toward a front end in operative association with push-out operation of the knock section (30); and the damper space (40) provided between the knock section (30) and the shaft tube (20), being sealed off from the outside, and changing its volume by push-out operation of the knock section (30).