Electrochromic Properties of Zincphthalocyanine Vacuum Evaporated Thin Films Kohji Kato, Student Member, Masayoshi Masui, Member, Fujio Kaneko, Non-member, Manabu Takeuchi, Member (Ibaraki University) Amorphous and polycrystalline zincphtalocyanine thin films were deposited in this study, on indium tin oxide (ITO) substrates by means of a vacuum evaporation technique, and their electrochromic properties were investigated in the electrolytic solution of 0.5M natriumchloride solved in ethyleneglycol. Basic characteristics of electrochromism were measured and observed as following: cyclic voltammetry, electron and anion behavior, VIS spectroscopy, coloration efficiency, memory properties and response time. The color transition was observed from blue to purple upon oxidation and from purple to blue upon rereduction. When potential was swept in a potentiogalvanostat, charge compensation was attained upon oxidation by injection of anions from the electrolyte to the thin film and upon rereduction by expulsion of anions. As anions may be more easily injected in amorphous films, those showed electrochromism more clearly oxidized state with a purple color of zincphthalocyanine was stably stored even in air.