An analysis of different structures of the spiders supporting the flat mirror of a Newton type telescope was made, in order to reduce the diffraction effects of the spider on the images produced by the telescope. After applying different numerical solutions used by different authors, and without satisfactory results, a novel solution based on the analysis of the diffraction pattern of a circular aperture allowed us to find a satisfactory reduction of the diffraction pattern in the image produced by the support of the secondary flat mirror. Experimental laboratory results will be shown, using white and He-Ne laser light sources.