A server device is equipped with: a virtual client unit that generates screen data by running application software so as to execute drawing commands; an image encoding unit that compresses the screen data; a drawing command encoding unit that compresses the drawing commands; a band measurement unit that measures network band on the basis of a response packet that is transmitted from a terminal, which is connected to the server device over a network, in response to a packet that is transmitted to the terminal; a selection unit that selects whether the compressed screen data or the compressed drawing commands should be transmitted to the terminal in accordance with the measured band; and a packet transmission/reception that transmits either the compressed screen data or the compressed drawing commands as selected to the terminal. The server device prevents a delay in screen display at a client terminal in the event of a fluctuation in network band between a thin client server device and the terminal.