Abstract: An automatic lead advance for a mechanical pencil having a tubular casing, a conical member joined to the front end portion of the tubular casing, a ring fixed to the inner surface of the conical member, an annular pivotable member provided at the front side of the ring, a lead guide tube having a lead retainer, urged backward by a spring, adapted to the slidable in the axial direction, and positioned so that the portion of the front end surface of the pivotable member which is away from the fulcrum of pivotal movement thereof contacts the rear end portion of the lead guide tube, a ball chuck mechanism urged forward by a knock spring and adapted to be movable between the rear end surface of the ring and an end surface of a stepped portion formed on the inner surface of the tubular casing, and a stopper provided at the front end of an outer tube of the ball chuck mechanism and contacting at the front end surface thereof the portion of the rear end surface of the pivotable member which is close to the fulcrum o