A specified time is determined which is a worst-case (or the longest) time period assumed as a time interval required between the instant at which an interface block receives an exposed substrate from an exposure unit and the instant at which a post-exposure bake process of the substrate starts in a heating part. A waiting time is calculated by subtracting a transport time from the specified time. The transport time is a time interval actually required between the instant at which the interference block receives the substrate from the exposure unit and the instant at which the substrate reaches the heating part. The post-exposure bake process of the substrate starts in the heating part after a lapse of the above-mentioned calculated waiting time since the arrival of the substrate at the heating part.