An image reading device includes a contact plate, a frame, a carriage, and a flexible flat cable. The carriage includes a reading mechanism and a resin-made slider projectedly provided at both end portions of the reading mechanism in its extending direction, and reciprocally moves in a sub-scanning direction at a bottom surface side of the contact plate while the slider slides the bottom surface of the contact plate in the frame. The flexible flat cable is connected to an one side surface of the carriage so that a width direction thereof matches the main-scanning direction, is arranged so that a part continued from a portion where the flexible flat cable connects with the one side surface is curved in a U-shape to go around toward an underside of the carriage, and transmits an electric signal of the reading mechanism. The contact plate is applied with a fluorine coating.