PURPOSE: To obtain a processing machine superior in durability even in the case of a high temperature and high concentration of a developing agent by providing a means for controlling developing solution and specifying at least one of the materials of a developing bath and racks.

CONSTITUTION: Processing baths 32, such as the developing bath 20, a bleaching bath 22, and a fixing bath 24, are formed and each bath is provided with racks G3. The developing bath 20 containing an aromatic primary amine developing agent in a concentration of 0.15-0.50mol/l has a means for controlling temperature to> 40-50°C, and the material of at least one of the bath 20 and the rack 33 is made of one kind of resin, such as polyphenyene sulfide, polyphenylene oxide, polymethylpentene, polyetherether ketone, polyalkylene terephthalate, polyether-imide, polyethersulfone, or polysulfone.