Properties of the excited states of the La@C-82 anion have been investigated by laser flash photolysis measuring the fluorescence and absorption spectra. Transient absorption bands in the visible and near-IR region observed by the laser excitation of the La@C-82 anion were attributed to the excited triplet, which showed high electron-donor ability to viologen dication, yielding La@C-82 and viologen radical cation, establishing a reversible photoelectron transfer cycle.