An image scanner in which in scanning an image of a document placed on a scanner body, an image scanning device moves and scans the image of the document. In scanning an image of a document fed by a document feeder to the scanner body, the image scanning device moves to a predetermined scanning position and then scans the image of the document in the scanning position. When the image scanning device arrives at the scanning position, the image scanning device is pressed against a stopper that is positioned relative to the document feeder.