To confirm the operations of a plurality of process controllers constituting a process control system by a small number of simulators.

This simulator 10 for a process controller is provided with a control program storing part 11 for storing the control programs of n pieces of controllers, a plant equipment data file 12 in which the set data of plant equipment are recorded, n pieces of process controller emulation parts 13 for reading the control programs from the control program storing part 11 in order to carry out those control programs, and for emulating the operations of the process controllers by referring to the set data recorded in the plant equipment data file 12, and a network interface part 16 capable of making a monitoring device communicate with the n pieces of process controller emulation parts 13.