Microscopic observation was carried out on bleaching process of developed silver. Filamentary silver, especially formed at short time development, was bleached rapidly, while massive silver remained almost unbleached. In ordinary bleaching solution, filamentary developed silver, covered in thin gelatine layer, was rapidly bleached. The rate of bleaching of silver plate was, however, very slow over 0.3 hr. to 20 hr., whereas the rate of bleach-fixing was fast. Consequently, it seems the rate of bleaching of silver is virtually fast, but it is influenced by the silver halide formed on silver, the diffusing rate of bleaching agents in gelatine layer and, may be, by inhibiting materials on developed silver surface.