Patent ID: 8892242

Claim:
A robot system, comprising: a robot hand for transferring substrates stored within a storage unit in multiple stages along a vertical direction; a position detecting unit for detecting storage positions of the substrates stored within the storage unit; a clearance calculating unit for calculating a clearance between the adjoining substrates on the basis of the storage positions of the substrates detected by the position detecting unit; and an entry permission/prohibition determining unit for determining permission or prohibition of entry of the robot hand into a space existing right below a substrate to be transferred on the basis of the clearance calculated by the clearance calculating unit, wherein, when the substrate to be transferred is not stored in a lowermost stage of the storage unit, the entry permission/prohibition determining unit is configured to determine that the entry of the robot hand into the space is permitted if a clearance between a substrate to be transferred and a substrate existing right below the substrate to be transferred is equal to or greater than a first threshold value, and wherein, when the substrate to be transferred is stored in the lowermost stage of the storage unit, the entry permission/prohibition determining unit is configured to determine that the entry of the robot hand into the space is permitted if a clearance between the substrate to be transferred and a substrate existing right above the substrate to be transferred is equal to or less than a second threshold value.