A control method for a display system is provided. The display system includes a display device displaying an image, and a voice processing device which generates first voice data based on a first voice requesting a first-type operation belonging to a part of a plurality of types of operations to the display device and transmits the first voice data to a server device. The display device receives a command to execute the first-type operation from the server device. The display device includes a voice recognition unit recognizing a second voice requesting a second-type operation that is different from the first-type operation, and a control unit controlling execution of the first-type operation and the second-type operation. The voice processing device transmits the first voice data requesting a permission for the execution of the second-type operation, to the server device. The display device receives a command permitting the execution of the second-type operation from the server device. The control unit starts the execution of the second-type operation in response to the command permitting the execution of the second-type operation.