PURPOSE: To minimize the hardware in the architecture of an exchange simulator system by mounting a microprocessing unit, providing only each interface part as the hardware circuit and realizing a logic interface and an internal processing part by the software of the microprocessing unit.

CONSTITUTION: The titled device is provided with an exchange interface circuit being a physical/electric connection with an exchange processing unit 1, an external interface circuit 7 being a physical/electric connection part with an external simulating processing unit 8, a storage device 8 incorporating programs and data realizing the internal processing and the logic interface with the exchange processing unit 1 and the external simulating processing unit 2 and a microprocessing unit 9 utilizing the program and data stored in the storage device 8 to execute the function processing The function of the the device 3 is executed by the software plogram stored in the storage device 8 and the microprocessing unit 9 using the data. Thus, the equipment of the hardware is minimized.