A writing instrument comprising: a barrel extending along a central axis between a front end and a rear end provided with a front and a rear apertures (3, 5) respectively; a writing tip movable through the front aperture between an extended position and a retracted position for which said writing tip is situated within said barrel; an actuating mechanism comprising a plurality of parts for extending and retracting the writing tip upon actuation of an actuation member; and a cushioning device enabling a retraction of the writing tip when an excessive pressure is exerted thereon by an user, wherein said cushioning device comprises a spring member elastically deformable in said central axis direction, which is compressed by a retraction of the writing tip when said excessive pressure is exerted on the writing tip, wherein said actuating mechanism has a movable tubular part being movable relative to said barrel along said central axis, wherein said spring member has a free end abutting said barrel toward its rear end and has a through hole extending along said central axis; and wherein a stem extending within said hole of said spring member, connects said actuating member to said actuating mechanism, characterized in that said spring member of the cushioning device is integrally formed with said movable tubular part of said actuating mechanism, said spring member comprises a first portion and a second portion which are symmetrical to each other relative to a diametrical plane (VII-VII) containing the central axis, each of said first and second portions (37, 38) having an extension axis which is parallel to the central axis, and each of said first and second portions (37, 38) being wavy insofar as the first and second portions (37, 38) have at least one first curve (37a, 38a) and at least one second curve (37b, 38b), said first curves and said second curves of the first and second portions (37, 38) being on the both sides of the extension axis of said first and second portions (37, 38), the first and second curves of a portion (37, 38) being disposed alternately and forming a continuously curved shape without sharp edges, and said cushioning device further comprises an additional spring member formed by a metallic helical spring provided between said movable tubular part of the mechanism and said barrel, said additional spring member being compressed in the direction of the central axis by a retraction of the writing tip when said excessive pressure is exerted on the writing tip, to create a cushioning force together with the spring member. a barrel extending along a central axis between a front end and a rear end provided with a front and a rear apertures (3, 5) respectively; a writing tip movable through the front aperture between an extended position and a retracted position for which said writing tip is situated within said barrel; an actuating mechanism comprising a plurality of parts for extending and retracting the writing tip upon actuation of an actuation member; and a cushioning device enabling a retraction of the writing tip when an excessive pressure is exerted thereon by an user, wherein said cushioning device comprises a spring member elastically deformable in said central axis direction, which is compressed by a retraction of the writing tip when said excessive pressure is exerted on the writing tip, wherein said actuating mechanism has a movable tubular part being movable relative to said barrel along said central axis, wherein said spring member has a free end abutting said barrel toward its rear end and has a through hole extending along said central axis; and wherein a stem extending within said hole of said spring member, connects said actuating member to said actuating mechanism, characterized in that said spring member of the cushioning device is integrally formed with said movable tubular part of said actuating mechanism, said spring member comprises a first portion and a second portion which are symmetrical to each other relative to a diametrical plane (VII-VII) containing the central axis, each of said first and second portions (37, 38) having an extension axis which is parallel to the central axis, and each of said first and second portions (37, 38) being wavy insofar as the first and second portions (37, 38) have at least one first curve (37a, 38a) and at least one second curve (37b, 38b), said first curves and said second curves of the first and second portions (37, 38) being on the both sides of the extension axis of said first and second portions (37, 38), the first and second curves of a portion (37, 38) being disposed alternately and forming a continuously curved shape without sharp edges, and said cushioning device further comprises an additional spring member formed by a metallic helical spring provided between said movable tubular part of the mechanism and said barrel, said additional spring member being compressed in the direction of the central axis by a retraction of the writing tip when said excessive pressure is exerted on the writing tip, to create a cushioning force together with the spring member.