To improve work efficiency by shortening a carrying time in a carrier system for carrying workpieces between chambers partitioned by a gate.

A carrying locus A is set between a transfer chamber 20 provided with a carrying robot 21, and a process chamber 23 provided with the gate 24. A first point P1 in a distance that can stop a carried workpiece W not to contact the gate of a carrying destination chamber, and a second point P2 immediately before a workpiece tip mechanically interferes with the gate, are set on the carrying locus A. When the workpiece W reaches the first point, the time TR to reach the second point P2, and the time TG when the gate 24 has opening which does not contact the workpiece W, are computed from a speed pattern of the carrying robot 21. The carrying speed from the point P1 to the point P2 is computed from TR and TG for carrying, and during the opening/closing operation of the gate, the workpiece is carried passing through a gate position without contacting the gate.