To communize control process of an IC testing device, decrease size of application programs, facilitate developing work, and prevent control by plural application programs from causing malfunction.

For plural application programs 41, 42 which supply control requiring signals P1, P2 according to control instruction from an input device 10, and supply the control result to an output device 20 based on control result informing signals P4, P5, a communication management program 43 which manages signal transfer, and a control program 44 which controls an IC testing device 30 based on the control requiring signals are provided. Then, the control requiring signals from the application program 41 or 42 are supplied to the control program 44 through the communication management program 43, and the control program 44 controls the IC testing device 30 and sends its result to the application program 41 or 42.