To provide a development processing device with which temperature control can stringently be performed by suppressing the temperature rise of a development processing liquid.

Two cooling air trunks 51A and 51B are formed within a duct 51 provided with a single cooling fan 52 at its end and radiators R 1, R 2, and R 3 are arranged at a conduit 25 for circulating the development processing liquid L from a development processing tank 21 to the respective cooling air trunks 51A and 51B and are equipped with a valve body 57 for selectively sending the cooling air from the cooling fan 52 to the two cooling air trunks 51A and 51B such that, if there is the temperature rise of the development processing liquid L of the development processing tank 21, the cooling air from the cooling fan 52 is supplied to any of the set radiators R 1, R 2, and R 3.