Abstract: In a system for monitoring a vibration-isolated foundation, the system includes: an air pressure monitoring system for monitoring air pressure supplied to air mounts of the vibration-isolated foundation, wherein the air pressure monitoring system includes: a plurality of air ports configured to receive air to be supplied to the air mounts; a plurality of pressure sensors, each of the pressure sensors being configured to measure the pressure of the air supplied to a corresponding one of the air ports and to output the measured pressure as a sensing signal; a control unit configured to receive the sensing signal from each of the pressure sensors and to output a control signal according to a measured value of each of the pressure sensors; and a notification unit configured to operate according to the control signal of the control unit.