A substrate processing apparatus according to the present invention is provided with a spin chuck that holds a substrate and rotates the same. The first device is coupled to a far end of a first network. At the bottom of the seat is a transverse surface. The disclosed intrusion detection and response system is also implemented at low cost using currently-existing hardware and software. At least one resilient restoring member is disposed between the locating member and the layout fixing seat for restoring the locating member to its home position.