Photovoltage generation was observed for C60/Si heterojunction fabricated by the deposition of C60thin film on Si substrate. Four types of Si substrates (two forp‐type and two forn‐type) were used. All junctions showed rectifying behaviors and photovoltage generation under illumination of Ar‐ion laser. The highest value of the photovoltage was 0.40 V. From the saturated photovoltage values for four junctions, the Fermi level of C60thin film was estimated to be located about 4.7 eV below the vacuum level. ©1996 American Institute of Physics.