To make the power consumption of a slave unit small by providing plural infrared-ray communication means in the slave unit in a system, for which the plural slave units are installed to a master unit and making the specified infrared-ray communication means and a specified equipment to be controlled correspond to each other.

To the slave unit 101e installed in a living room 1f, an equipments to be controlled personal computer 2, an air conditioner 112e, a TV 113b and a VTR 114 are present. The slave unit 101e is provided with a table for indicating the order of the communication quality of light-emitting modules to the respective equipments to be controlled or the table for indicating the module of the bent communication quality to the respective equipment to he controlled. If needed, the tables may be provided in the master unit and downloaded to the slave unit. Since the addresses of the master unit, the slave unit and the equipment to be controlled and a light-receiving and emitting module codes, etc., are stored, the slave unit makes only one required module emit light, without making all the modules to be infrared-ray communication means emit the light.