Abstract: The invention relates to drum processing apparatus for in the treatment of photographic material. The apparatus comprises a stand, a processing drum rotatably mounted on the stand, and means for intermittently axially displacing processing liquid in the drum causing the liquid to oscillate axially in waves traversing the length of the drum. The drum is axially slidable relative the support. During rotation of the drum, it is variably axially displaced against drum biasing means to cause processing liquid in the drum to oscillate axially. The present apparatus, which is simple and convenient to construct, ensures uniform and continuous contact of the processing liquid over the photographic material treated in the drum.