Method of controlling substrate transfer system and the substrate transfer system

A substrate transfer system comprising:

• a transfer mechanism having a holder configured to hold a substrate and configured to transfer the substrate, and a measurement part configured to detect an outer periphery of the substrate being transferred by the transfer mechanism and measure a center position of the substrate, so as to transfer the substrate to a target position;
• and
• a controller configured to control the transfer mechanism,
• wherein the controller is configured to:
• correct the target position based on an amount of positional deviation between a reference position of the holder and the center position of the substrate measured by the measurement part, a first amount of thermal displacement of the reference position of the holder by a thermal expansion of the transfer mechanism at a measurement position where the outer periphery of the substrate is detected by the measurement part, and a second amount of thermal displacement of the reference position of the holder by the thermal expansion of the transfer mechanism at the target position to which the substrate is to be transferred;
• and
• control the transfer mechanism such that the reference position of the holder becomes the corrected target position.