Abstract: In order to ensure the security by access control, or the like, using a limited input/output interface of a household electric appliance without complicated setting manipulations, a refrigerator includes a filter section which permits only establishing a communication with a relay server having a specific IP address. The relay server includes a relay control section for relaying a communication between the refrigerator and a cellular mobile phone or a personal computer, a connectable device database in which a partner device whose communication is permitted by the relay control section to be relayed is registered in conjunction with the refrigerator, and a data conversion section for performing data conversion at the time of the relay according to a difference in the input/output interface between the refrigerator and the personal computer, or the like. The refrigerator and the personal computer, or the like, can establish a communication through the relay server.

Abstract: For the purpose of associating a device having a sensor with a device which utilizes a detection result so as to enable various operation control, a refrigerator includes a temperature sensor for detecting a compartment temperature, a storage section for storing a detection result, an information association control section for controlling transmission of the detection result to a microwave oven, and the like, and an NIC for communicating with the microwave oven through a network, or the like. The microwave oven includes an NIC of the same type, an information association control section for controlling reception of the compartment temperature transmitted from the refrigerator, and the like, and a principal part control section for controlling the operation of principal part of the microwave oven. The microwave oven heats food taken out of the refrigerator by performing heating control according to the compartment temperature at the time when the food is taken out of the refrigerator, i.e.