A pneumatic system operation control device for variable control of the rotation speed of an electric motor for driving an air-compressor such that constantly supplied pressure to a terminal device is achieved in accordance with a discharge pressure measurement value of the air-compressor and a supply pressure measurement value to the terminal device. The control device: stores the discharge pressure measurement value and the supply pressure measurement value; and, upon receiving input of an air pipe network model composed of data for calculating a flow of air in an air pipe network, calculates a flow rate of air supplied to the terminal device and an update value of a control setting value, and updates the control setting value to be used for variable control on the basis of the update value.