A multi-purpose writing device comprising plural writing elements, at least one of which is an automatic pencil that can be extended, can be extended to and retracted from and between the writing position and the housed position alternately by rotating a cylindrical cam. The cylindrical cam is sectioned diagonally with respect to the axis at its lower end to form a cam surface and is also provided with a translation cam inside thereof to provide a two-stage cam mechanism. Further, a flat portion is made at the top and the bottom of the cam surface provided at the lower end of the cylinder member. A slider which connects with each writing element is stepped to provide slide projections while slide against the cam surfaces. The axial movement of the cylindrical cam is transmitted to the automatic pencil element by the engagement of the translation cam with the slide projections to cause the lead of the pencil to be discharged.