The invention relates to a device for checking the authenticity of an anti-forgery marking with colors which change depending on the angle of observation, comprising a) several first light sources, emitting in a given spectral range, whereby the light sources are different from each other with regard to the wavelength of the emission maximum thereof and the first light sources (1) are housed in a housing (5) such as to irradiate the surface (O), with the housing (5) placed thereon, at a given first angle (α1), b) a first means (2) for measuring the intensity of the light reflected from the surface (O) arranged at a second angle (α2) and c) a means (7) for the automatic comparison of measured intensities with the reference intensities stored for at least one given color for each light source (1).