Abstract: Processing apparatus for image-wise exposed light-sensitive sheets of the DTR-type, which comprises a trough (11) for processing liquid, a sloping entry guide plate (17) for guiding a sheet towards its deepest point, a pair of outlet rollers (16) for pulling a sheet at a uniform speed through the apparatus and for squeezing liquid from it and replenishing means for keeping a processing liquid in the trough at a controlled level, which apparatus is provided with a floating cover (25) arranged for floating on the free surface of the processing liquid, and means for maintaining between the rear edge of the floating cover and the rear end of the trough a space (41) sufficient to allow unhindered passage of a processed sheet towards the outlet rollers.