To provide an infrared communication device of an information processor which never deteriorates the operability and the freedom of placement for its peripheral device and also never produces electrical noises for the transfer of information.

An infrared communication device 4 prepared for a personal computer main body is provided with the optical cables 11 and 12 which are connected to each other via one of both ends of each of them and transmit the infrared rays sent or received from the device 4, and an optical terminal 13 which is connected to the other end of each of both cables 11 and 12 and receive and transmit the infrared rays sent through the cables 11 and 12. In such a constitution, the infrared communication is possible between a peripheral device of the device 4 and the terminal 13. Then the position of the peripheral device is not restricted together with improvement of its operability and freedom of placement as long as the terminal 13 is placed at an optional position. Furthermore, the electrical signals are never produced even when the information is transferred at a high speed.