| 摘要 |
The present invention teaches a retreat permission position of a carrier arm when the carrier arm is moved back to retreat outside a mounting table after the carrier arm carries a substrate to a position above the mounting table while holding a peripheral portion of the substrate, to thereby place the substrate on a plurality of supporting pins vertically movable through the mounting table. The present invention has a disk substantially equal in size to the substrate, having insertion holes formed to allow the supporting pins to be inserted therethrough and being supportable by the carrier arm, and a sensor capable of detecting whether or not the supporting pin inserted through the insertion hole of this disk exists. After an output signal is received from the sensor, a position to which the carrier arm is to be moved in a vertical direction relatively to the disk from a detection position of a tip of the supporting pin is calculated by an operation, an amount of this movement exceeding at least a thickness of the carrier arm, and this position is taught as the retreat permission position of the carrier arm.
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