Abstract: A laser having an adjustment device for varying the output power of the laser. The adjustment device has an adjustment element which is switched in by the operator but cuts out automatically. Using a beam splitter, part of the laser beam is directed on to a light-sensitive element in order to determine the laser power. The values of the selected and instantaneous output power are indicated on the display of a display unit. The adjustment element can be switched in using only one hand and, with the adjustment element switched in, the laser power required can be adjusted using only one hand.