The object of the present invention is, in a device control system that controls devices within a house, to reduce the effort required of a user during authentication, as well as to prevent unauthorized access by a third party. A device control system access restriction method includes the steps of accepting registration of terminal information for associating an identifier unique to an operating terminal with operating terminal access right, of accepting instruction information including operating terminal identifier and instruction signals relating to operations of a device, of determining the access right of an operating terminal based on the operating terminal identifier included in instruction information, and of controlling the device based on operating terminal access right and instruction signals relating to that device.