To provide an ultrasonic engraving pen which dispenses with a great pressuring force in engraving, and hardly deteriorates the engraving performance even in a long-time use, regardless of the electric conductivity of an object to be engraved.

This ultrasonic engraving pen, in which a piezoelectric vibration complex, which is composed of a single piezoelectric vibrator 104 or a combination of the vibrator 104 and a displacement enlarging cone 101, is driven almost at a resonance frequency, so that the engraving can be applied onto the surface of a hard object, is characterized in that the area of a vibrating tip part is set at 1 mm2 or less, and the ultrasonic engraving pen is provided with a vibrating tip part where diamond powder is electrodeposited or a vibrating tip part where carbon steel is quenched.