An image scanning device includes a base part; and multiple image sensors each including a substrate, a line sensor including scanning elements arranged on the substrate, and a holder for holding the substrate. The base part holds the image sensors such that the scanning elements of an image sensor partly overlap the scanning elements of an adjacent image sensor in the main-scanning direction. The coefficients of linear expansion of the substrate and the base part are substantially the same; the holder and the base part are fixed together at a first fixing point; the holder and the substrate are fixed together at a second fixing point; and the distance in the main-scanning direction between the first fixing point and the second fixing point and the direction of the second fixing point with respect to the first fixing point are the same for all the image sensors.