An industrial plant monitoring system includes: a first terminal attached to a worker and having a gyro sensor generating inclination information based on a movement of the worker; a server receiving the inclination information; and a second terminal configured to communicate with the server. The server performs processing of acquiring a number of pieces of the inclination information generated during a predetermined period and exceeding a predetermined inclination angle, processing of determining whether the acquired number of pieces of the inclination information exceeds a predetermined value or not, and processing of transmitting first alarm information to the second terminal when it is determined that the number of pieces of the inclination information exceeds the predetermined value.