PURPOSE: To provide a wire-cutting apparatus wherein removal of processing dust is effectively carried out by causing high frequency vibration such as of ultrasonic wave in a wire electrode, a short circuit being eliminated, and processing being stably advanced.

CONSTITUTION: A wire electrode 1 travels between guides 2, 3 in the direction of arrows or in the opposite direction thereof. Vibration by a trembler 4 gives vibration to the wire electrode 1 which comes into contact with a hard member 6 such as sapphire at a pointed end of a vibrating horn 5. An object 8 to be processed is fixed between the guide 3 and the member 6, a processing liquid being sent from a processing liquid-feed pipe 10 to a liquid-surrounding member 9, a liquid-feed nozzle 11, and a processing site. Since a wavy vibraton is given to the wire electrode, processing dust and bubbles are well removed, and stable processing is achieved.