The present invention provides a gateway device releasing information and service information of an appliance to an appliance connected to a network having a different protocol. The gateway device includes a device description creation processing unit, a device description template holding unit, a service description creation processing unit, and a service description template holding unit. The service description creation processing unit categorizes services and attributes that each appliance can provide into property types, which are control models, and based on a rule defined for each property type, a service information description, which is information to be released, is automatically created.