The Sunyaev Zel'dovich effect is one of the most powerful tools in cosmology. I will review the basics of the interaction between the Cosmic Microwave Background Radiation and the ionized medium mainly present in Galaxy Clusters highlighting the cosmological information that can derive from SZ effect measurements. I will present instrumentation and observational techniques for millimetric radiation focusing mainly on the "Millimeter & Infrared Testagrigia Observatory" (MITO) observations, the recent results from the "Atacama Cosmology Telescope" (ACT) and the upcoming measurements of the OLIMPO ("Osservatorio nel Lontano Infrarosso Montato su Pallone Orientabile") experiment.