To provide a method for controlling the vibration pen of a engraving machine so that engraving starts immediately after the arrival of the pen at a work irrespective of the distance between the pen and the work.

A vibration pen 1 descends with a stylus 1A vibrating at a high speed. When the pen 1 moves while pushing the surface of a work 10 at a given pressure, the work 10 is engraved. A floodlight 2A and a light receiver 2B are arranged to reduce light receiving output with the descent of the pen 1. The light receiving output is converted into digital values by an A/D converter 3. The digital values are monitored by a CPU 4. When the decrease of the values stops, and when the CPU 4 commands to move the pen 1, the pen 1 moves without waiting at an engraving start point, preventing the quality of the engraving from being deteriorated.