To constitute a development processor capable of shortening the processing time of stabilization processing by linearly conveying a photosensitive material and discharging a downstream-side photosensitive material even if the linear conveyance path is clogged upstream.

An out-tank processing rack 50 which horizontally conveys photographic paper while supplying stabilization processing liquid is arranged above one stabilization processing tank, and a transmission system is constituted which transmits driving power to an introduction roller 52 and a front conveying roller 53 introducing the photographic paper in the out-tank processing rack 50 from a system conveying the photographic paper in a previous processing tank and also transmits driving power to a rear conveying roller 55 and a discharge roller 56 sending the photosensitive paper out of the out-tank processing rack 50 from a system conveying the photographic paper in a following processing tank.