Abstract: A mechanical equipment monitoring system includes a sensor, an actuator, a communication unit that transmits a trigger signal when the actuator is in a suitable state for the sensor to detect an operational state of the actuator, an information collection unit that collects, from the sensor, operational state data which indicates the operational state detected by the sensor upon receiving the trigger signal from the communication unit, and an information processing device that monitors the actuator based on the operational state data collected by the information collection unit.