To reduce a cost in developing an applicable product by unnecessitating a special interface (circuit) to be required in an application program and also a program for controlling the interface in a computer using sensors.

Detection by the sensor is replaced with a keyboard input signal, easily inputted to the computer without using a special interface control program and also easily processed in a program. An event is detected by a detection sensor 1, the detection signal is transmitted to the CPU 3 of a keyboard and, then, the CPU 3 recognizes which one of the sensors performs detection. The CPU 3 of the keyboard 2 transmits an instruction to generate a character code assigned to the sensor which performs detection to a keyboard signal generating circuit 4 and also transmits an instruction to generate a break code to the keyboard signal generating circuit 4. The keyboard signal generating circuit 4 is connected to the computer 5 with a keyboard cable 7 and a signal flowing in the keyboard cable 7 is adopted as a keyboard signal of the computer 6.