A network system enables controlling an image input device without requiring a driver that depends on the computer environment. A client terminal 2 has a web page acquisition means 71 that acquires a web page 21 having an embedded scanner control script 24 that controls image input from a scanner 3; an image acquisition request transmission means 72 that sends an image acquisition request through an interface board 5 to the scanner 3 as controlled by the scanner control script 24; and an image acquisition means 73 that gets an image from the scanner 3 as a response to the image acquisition request as controlled by the scanner control script 24; and interface board 5 connected to the scanner 3 has a process request receiving means 81 that receives the image acquisition request, and a board-side image transmission means 83 that sends the image scanned by the scanner 3 based on the received image acquisition request to the client terminal 2.