PURPOSE: To enable both of enhancement of development speed in a developing bath for processing the photosensitive material by immersing it in a developing solution and reduction of air oxidation of a developing agent in a recirculation route.

CONSTITUTION: The automatic developing machine comprises a developing bath 1V for immersing the photosensitive material in the developing solution and developing it, the recirculation routes 2V, 4V, 23V, 24V, and 25V, connected with the bath 1V, for recirculating the developing solution, and a means 3A for feeding a solid processing agent, and the photosensitive material is subjected to the development processing by satisfying Vw≤Vf where Vw (l) is the volume of the developing solution contained in the bath 1V, and Vf is the volume (l) of the developing solution held in the routes 2V, 4V, 23V, 24V, and 25V.