A photographic paper processor includes plural serially arranged liquid baths, for sequentially processing a first photographic paper sheet of one type. The plural liquid baths are constituted by bath groups G1 and G2. The bath group G1 includes a color developing bath. The bath group G2 is positioned downstream from the bath group G1, and includes rinsing baths. First and second motors are operable individually, and rotate to transport the first paper sheet through respectively the bath groups G1 and G2 at a speed V1. A controller sets the bath group G1 at a speed V2 according to information of a second photographic paper sheet of a different type for processing next to the first paper sheet. Subsequently, the bath group G2 is set at the speed V2, to transport the second paper sheet through the plural liquid baths at the speed V2.