The liquid jet scalpel e.g. water jet scalpel (10) has nozzle (12) for discharging pressurized liquid (14) such as water in the direction of a to-be-manipulated fabric (16). A distance measuring device (18) measures the distance between the nozzle and to-be-manipulated fabric. The distance measuring device are interferometer, acoustic spacing measuring device and ultrasound measuring device. An independent claim is included for method for operating liquid jet scalpel.
