Substrate carrying mechanism and substrate carrying method

A substrate carrying mechanism measures accurately a displacement of a substrate provided with a notch in its edge on a holding fork when the substrate held by a holding fork is carried, corrects accurately the displacement, and corrects the state of the holding fork. The substrate carrying mechanism includes: a base; a substrate holding member 3A placed on the base and capable of holding a substrate W and of being advanced and retracted relative to the base; four or more detecting units 5 respectively for detecting different parts of the edge of a substrate held by the substrate holding member 3A when the substrate holding member 3A holding a substrate W is retracted; and a controller that determines whether or not a notch WN formed in the edge of the substrate W has been detected by one of the detecting units 5, on the basis of measurements measured by the four or more detecting units 5 and corrects an error in a transfer position where the substrate is to be transferred to the succeeding processing unit on the basis of measurements measured by the detecting units 5 excluding the one detecting unit 5 that has detected the notch WN of the substrate W.