To investigate the possibility of photoinduced controllability of an electrochemical element, using agarose gel, amino acids, and a hydrogenated amorphous silicon (a-Si:H) thin film, an electrochemical element, which constituted the fluorine doped tin oxide glass (FTO/glass) transparent conductive positive electrode, 2 mm thick 0.05 M-Asp gel, 2 mm thick 0.05 M-Arg gel, a-Si:H film (hydrogen 0-40%, thickness 16.2 nm), a-Si:H film (hydrogen 20%, thickness 81 nm), and FTO/glass transparent conductive negative electrode, was constructed. The visible-light-induced current vs a potential behavior was measured by potential step method. Compared with the case of hydrogen concentration of ðlayer 1; layer 2Þ ¼ ð20%; 20%Þ, in the case of ð20%; 40%Þ current vs potential increased. On the other hand, in the case of ð20%; 0%Þ, current became smaller than that in the ð20%; 20%Þ. From these results, a new application aspect of a-Si:H for the control of ion conductivity in organic molecules was revealed.