A writing instrument includes a cylindrical outer housing, one end of the outer housing having an outer opening, and an electronic pen body stored in the outer housing. The electronic pen body includes a stylus, one end of the stylus in an axial direction of the stylus serving as a pen tip, and a cylindrical inner housing storing the stylus, the one end of the stylus serving as the pen tip extending from an inner opening at a distal end of the inner housing, the inner opening of the inner housing defining one axial end of a hole extending axially forming a stylus guide that enables the stylus to move axially. In operation, the pen tip of the stylus and a distal portion of the inner housing having the inner opening extend from the outer opening of the outer housing.