In manufacturing a functional plastic lens by loading a functional sheet S having a difference in the accuracy of bending in directions, into a mold 50 and by performing insert molding to integrally mold a lens body with the functional sheet S, a direction in which the accuracy of the bending to the functional sheet S is high is made to be a reference axis A, and the functional sheet S is loaded into the mold 50 to inhibit a filling direction of resin and the reference axis A from being orthogonal to each other. With this arrangement, the functional plastic lens having high quality is provided.