PURPOSE: To provide a home automation system in which a transmitting efficiency can be improved, and the bit length of a frame can be short.

CONSTITUTION: In the home automation system equipped with not only a home bus(main bus), but also a sub-bus such as a radio wave and an infrared ray, conventionally the transmission origin address and transmission destination address of the home bus are inputted to the address field of the frame used for the transmission, and the actual transmission origin address and transmission destination address of the sub-bus are inputted to the other fields. On the contrary, the actual transmission origin address and transmission destination address are inputted to an address field 3 of a frame 1, and a transmission origin bus designation and a transmission destination bus designation is operated by 4 bits of a control filed 4 as indicated by a figure, so that the bit length of the frame can be short, and the transmitting efficiency can be improved.