Abstract: A Laser device with phase front regulation, including a resonator with a beam path, a laser medium located within the resonator, and a phase front regulating unit located within the resonator; a coupling element; an uncoupling element; and phase front controller and a phase front sensor. A measuring laser beam can impact first the coupling element, then the laser medium, then the phase front regulating unit, then the uncoupling element, and then the phase front sensor. The disturbance of the phase front of the laser medium is transferable to the measuring laser beam. The disturbance of the measuring laser beam and the working laser beam can be corrected by the phase front regulating unit. Sensor data can be received from the phase front sensor and can be processed by the phase front controller. Regulating unit signals for the phase front regulating unit can be generated by the phase front controller.