To reduce the number of components, to lower a cost, to perform a processing in a short time and to provide stable processing performance at all times.

In an automatic developing device 1 for a sensitive material for carrying an exposed sensitive material to a processing part 2 and processing the sensitive material with a processing liquid of the processing part, three or more stabilization vessels are successively arranged and provided in the processing part 2 and only the stabilization vessel on a center side among the three or more stabilization vessels is temperature-controlled by using a heating processing part.