A laser device having a semiconductor body (1), which has a plurality of active layers (5, 9) arranged vertically one above the other and serving for generating laser radiation. The active layers are subdivided in the transverse direction into a plurality of emission zones (15) and are electrically connected in series in the vertical direction. The semiconductor body (1) is formed in monolithic integrated fashion, and a cooling element (2) is provided on which the semiconductor body (1) is arranged.