TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: Optionally, salt or chelate compound of metal other than copper is used during manufacture of processed metal oxide semiconductor particle such that copper containing metal sulfide (c) is adhered to semiconductor particle. Metal oxide semiconductor particle is added to solution of copper salt or chelate compound and subsequently ion source compound is added to form processed metal oxide semiconductor particle. The contact process is performed by ultraviolet irradiation. During manufacture of electrode, heating, pressurization, ultrasonic welding, microwave irradiation, ultraviolet light irradiation and/or ozone treatment are performed to semiconductor particle.Preferred Property: The average secondary particle diameter of metal oxide semiconductor particle is 10-500 nm. Preferred Compound: The ion source compound is ammonium sulfide. The copper containing metal salt contains divalent zinc, trivalent indium, trivalent gallium, tetravalent tin and monovalent copper. The semiconductor particle is composite metal oxide semiconductor particle having metal oxide semiconductor (b) on the surface of metal oxide semiconductor particle (a). The composite metal oxide semiconductor particle is obtained by oxidizing precursor of particle (b) in the presence of particle (a). Particle (a) contains titanium, zinc, tin and niobium. Particle (b) contains magnesium, aluminum, silicon, scandium, titanium, zinc, gallium, germanium, strontium, yttrium, zirconium, niobium, indium, tin, barium, lanthanum and/or tantalum. The content of copper containing metal sulfide is 1-300 wt.pts with respect to 100 wt.pts of metal oxide semiconductor particles.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compound: The precursor of particle (b) is coordinate or ionic compound of formula (1).M=metal atom of 1-6 valent;R1-R3=H or univalent substituent;andbroken line=non-localized bonding in diketonate compound structure. EXAMPLE - Dispersion of zinc acetylacetonato and P25 (RTM: titanium oxide) was sintered at 400degreesC after removing the solvent. Ammonia aqueous solution (10 g) of cuprous chloride was added after grinding the obtained particle. The particle was re-dispersed. Ammonium sulfide aqueous solution containing copper sulfide was dropped to form processed metal oxide semiconductor particle comprising copper metal sulfide. Electrode was formed using the semiconductor particle. Further, photoelectric conversion cell comprising the obtained electrode, glass substrate with fluorine doped tin oxide layer (counter electrode), and electrolyte was formed. The photoelectric conversion cell had photoelectric conversion efficiency of 1.15%.