To provide a network terminal device and its image inputting method which improve user's operability when an image input device capable of being shared on a network inputs an image from a terminal device connected to the.

When an image input device capable of being shared on a network inputs an image, this image inputting method instructs the image input device to read an image (S501), discriminates whether an image read processing mode in the instructed image input device is a mode showing a window or a mode that does not show the window (S502) and displays an alarm message when a discriminated result is the mode showing the window (S503).