An image reader configured to focus light emitted from a light source and reflected by an object-to-be-read, and to read an image of the object-to-be-read, the image reader comprising: - a board; - a light source; - a line sensor assembly including a plurality of photosensitive elements formed on one surface of the board along a main scanning direction; - a lens array assembly including a plurality of lenses arrayed along the main scanning direction, and configured to focus the reflected light onto the line sensor assembly; - a light shield configured to support a portion of the lens array assembly at the line-sensor assembly side, and to block light other than the light focused by the lens array assembly; - a transparent member made of transparent material retaining the lens array assembly and the light shield in a retainer space and configured to guide the light from the light source through an interior of the transparent member, and emit the guided light to the object-to-be-read, and covering a portion of the lens array assembly at the object-to-be-read side and the light shield; and - a fastener (2c, 2d, 2e, 2f, 2k, 9, 16, 17, 18, 19) configured to fasten the transparent member to the board, and by pressing force from the board by the fastening, to bring the light shield into contact with the transparent member, to bring the lens array assembly into contact with the transparent member via the light shield, or to bring the light shield and the lens array assembly into contact with the transparent member, - the fastener (2c, 2d, 2e, 2f, 2k, 9, 16, 17, 18, 19) being an engagement portion provided to the transparent member, a boss formed on the transparent member, a screw, a clip, an adhesive, or a combination of an elastic member with projections formed on the respective surfaces of the transparent member located opposite to the retainer space. - a board; - a light source; - a line sensor assembly including a plurality of photosensitive elements formed on one surface of the board along a main scanning direction; - a lens array assembly including a plurality of lenses arrayed along the main scanning direction, and configured to focus the reflected light onto the line sensor assembly; - a light shield configured to support a portion of the lens array assembly at the line-sensor assembly side, and to block light other than the light focused by the lens array assembly; - a transparent member made of transparent material retaining the lens array assembly and the light shield in a retainer space and configured to guide the light from the light source through an interior of the transparent member, and emit the guided light to the object-to-be-read, and covering a portion of the lens array assembly at the object-to-be-read side and the light shield; and - a fastener (2c, 2d, 2e, 2f, 2k, 9, 16, 17, 18, 19) configured to fasten the transparent member to the board, and by pressing force from the board by the fastening, to bring the light shield into contact with the transparent member, to bring the lens array assembly into contact with the transparent member via the light shield, or to bring the light shield and the lens array assembly into contact with the transparent member, - the fastener (2c, 2d, 2e, 2f, 2k, 9, 16, 17, 18, 19) being an engagement portion provided to the transparent member, a boss formed on the transparent member, a screw, a clip, an adhesive, or a combination of an elastic member with projections formed on the respective surfaces of the transparent member located opposite to the retainer space.