Substrate processing apparatus and method of operating substrate processing apparatus

A substrate processing apparatus, comprising:

• a substrate transfer mechanism configured to advance and retreat a holding body that holds a substrate by bilaterally symmetrically arranging two link mechanisms each including a driving arm and a driven arm connected to each other so as to horizontally rotate, connecting the holding body at a leading end of each of the driven arms of the link mechanisms so that the holding body horizontally rotates, and horizontally rotating the driving arms synchronously by a driving part;
• a processing module configured to process the substrate in a heated state, the substrate being transferred by the substrate transfer mechanism;
• a rotation angle measuring part configured to measure a rotation angle of at least one of the driving arms;
• a holding body detection part configured to detect that a specific portion of the holding body is located at a predetermined position;
• and
• a controller configured to execute a step of acquiring a measurement value of the rotation angle of at least one of the driving arms when the specific portion is detected by the holding body detection part by positioning the specific portion of the holding body at the predetermined position at preset time intervals, a step of obtaining a moving average of a preset sampling number for the measurement value of the rotation angle based on time series data of the measurement value of the rotation angle acquired in the step of acquiring the measurement value, and a step of obtaining a correction amount of the rotation angle of at least one of the driving arms obtained in advance so that a substrate transfer position of the holding body of the substrate transfer mechanism for the processing module becomes a reference position, according to a comparison result between a value of the moving average and a value of a reference rotation angle which is a rotation angle of at least one of the driving arms when the specific portion of the holding body of the substrate transfer mechanism at a reference temperature is located at the predetermined position.