To provide a preliminary drying device and method, and a substrate treating system, suppressing occurrence of unevenness on a coated film, and shortening a tact time required for a drying process.

The preliminary drying device for preliminarily drying the coated film before drying the coated film by a main drying device for drying the coated film coated on a substrate has a heating and drying chamber communicated with a carrying-in part and a carrying-out part and formed in the high temperature atmosphere, and the substrate carried from the carrying-in part is made to pass through the heating and drying chamber by the carrying-out part, and thereby, the substrate is exposed to the high temperature atmosphere in the heating and drying chamber, and the coated film on the substrate is preliminarily dried.