Abstract: The invention relates to a drilling device for hard rock using a fluid, having at least one drill head with a pre-chamber and a mixing chamber where at least one front-facing nozzle and at least one rear-facing nozzle are provided. The fluid is mixed with abrasives in the mixing chamber, and the fluid together with the abrasives exits from the front-facing nozzle or an opening. The fluid flow is separated in the region of the pre-chamber, abrasive-free fluid exits the rear-facing nozzles, abrasives and the abrasive-free fluid are mixed in the mixing chamber, and the fluid mixed with the abrasives exits from the front-pacing nozzle or an opening.