The near field of a semiconductor laser was measured by using a Scanning Near Field Optical Microscope (SNOM). The near field emission was recorded during the scanning of the fibre tip above the facet of the semiconductor laser at a distance less than 20 nm. By controlling the shear force the topography of the facet was recorded simultaneously. The waist radius, the divergence and the M2-factor of the semiconductor laser were obtained by measuring the beam images in different positions along the propagation.