Recently, the p-type doping by the adsorption of acceptor molecules on surfaces has been investigated in order to control the electronic properties of substrates. Valence and core-level photoelectron spectroscopy, X-ray absorption spectroscopy, scanning tunneling microscopy etc. have been utilized to elucidate the electronic structures and adsorbed states. In this article, recent studies on the adsorption of F4TCNQ on various surfaces are reviewed.