Abstract: A known method of manufacturing, for example, lasers comprises the deposition, on a substrate (1), of semiconductor layers from a gas (3) which includes at least two reactive components, such as TMG and arsine to form GaAs. The substrates (1) are arranged, within a reactor (10), on a supporting plate (2), heated and, preferably, rotated about their own center and the center of the supporting plate (2). Arsine (4) is supplied centrally above the supporting plate (2), and TMG (5) is supplied directly around said arsine, but separated therefrom, said TMG terminating at a larger distance from the supporting plate (2). These gases (4, 5) then flow sideways across the supporting plate (2) covered with substrates (1) and are discharged at the side thereof. Such a method results in a good homogeneity of the properties of the deposited semiconductor layer, which is crucial to many semiconductor devices.