X-ray photoelectron spectroscopy and high-resolution ultraviolet photoelectron spectroscopy studies were performed on thin Pu layers and compared with the studies on bulk surfaces prepared at various temperatures. We followed the process of reconstruction of the α-Pu surface into a δ-Pu type. Its kinetics depends strongly on temperature. The electronic structure of Pu layers varies markedly with the thickness and the localization of the $5f$ states can be achieved in the case of ultrathin Pu layers deposited on Mg. The valence band displays for the majority of Pu systems three sharp features within the first eV below the Fermi energy, the position of which is fixed. The localized $5f$ states yield a broad maximum at 1.6-eV binding energy.