This invention is to a writing tool such as mechanical pencil or a ballpoint pen in which a writing shaft having a head member is inserted in an outer sleeve in such a manner that the head member projects from the outer sleeve. A stair or step and a spiral groove are provided on the forward inner surface and the rearward inner surface of a tubular cap, respectively, with an inside diameter of the rear part of the spiral groove being larger. A bearing part is brought into contact with a lead tank provided inside a forward art of the tubular part so that the forward part of the outer sleeve is movable in the axial direction and is locked in the turning direction against a rearward inner surface of the outer sleeve. The rearward part of the tubular body is provided with a slit, holding pieces of a stick-shaped object holder slidably inserted in said slit. A stick-shaped object is held by the holding pieces, and the projection is provided on each holder engaged with the spiral groove of the tubular cap.