A solid-state image sensing device is provided with n one-dimensional pixel arrays for sensing a document image by relative movement of the one-dimensional pixel arrays and the document image in a scanning direction. The solid-state image sensing device includes: an image readout circuit, commonly provided for the one-dimensional pixel arrays, for performing a horizontal readout operation from the one-dimensional pixel arrays with respect to image data acquired by sensing the document image, wherein a pixel array pitch of the one-dimensional pixel arrays in the scanning direction is set to at least (n+1)/n times as large as a pixel width of each of pixels constituting the one-dimensional pixel arrays in the scanning direction, where the symbol “n” represents a positive integer of 2 or more, and the symbol “/” represents division.