To engrave diversified marks freely on a lens through a marking method by permitting an engraving pen mechanism or work holding mechanism adapted to form marks of the work by compressing a pen tip onto the work under a predetermined pressure to be driven by means of a driving control part of a computer control.

The engraving pen mechanism 10 is given a predetermined horizontal two-dimensional movement via an X-axis driving mechanism and Y-axis driving mechanism constituted by a servo-motor or the like from a CNC device. These CNC device, X-axis and Y-axis driving mechanism operate to drive the engraving pen mechanism 10, and constitute a driving control part for computer-controlling the driving. Also, the pen mechanism 10 is constituted to be movable elevatably via a vertical driving mechanism such as a pneumatic cylinder by control from the CNC device. Furthermore, the pen mechanism 10 includes a piston type penholder part 12 in an outer casing, the nib at the tip of the penholder 12 operates to mark on the surface of a work W through loads of the penholder part 12, as a result, marks are engraved thereon.