Dye-sensitized anatase TiO2 (001) surface was prepared in the solution directly connected with an ultrahigh vacuum analysis chamber. We measured the ultraviolet photoelectron spectroscopy (UPS) and low energy electron transmission (LEET) of the dye-sensitized surfaces with and without illumination. The highest occupied molecular orbital (HOMO) and other levels showed different peak shifts in UPS when illuminated. The observations were discussed in relation to the device characteristics of a half photocell.