We have tried to develop a new methodology for realizing the imaging of adsorbed molecules prosecuting efficient electron transfer at metal oxide semiconductor interfaces. Photo-induced current measurements were performed for dye-sensitized solar cells having nanostructured TiO_2 electrodes covered with the Ru(II)-based sensitizers, and we confirmed that weak photoinduced current signals of several nA were highly discernible. The photocurrent measurement was successfully combined with the 2D raster scan of a diffraction-limited laser focal spot. We thereby established the basis of a photoinduced current microscopy toward the single-molecule detection of ultrafast electron transfer adsorbates.