An upper unit configured to open and close an upper portion of a lower unit includes: a first reading unit disposed in a medium transport path, the first reading unit being configured to read a surface of a transported medium; a substrate coupled to the first reading unit; a cable having one end and another end, the one end being coupled to a first coupling portion of the first reading unit, the other end being coupled to a second coupling portion of the substrate; and a facing portion facing the lower unit in a state in which the upper unit is closed, the facing portion being configured to be attached to and detached from the upper unit. The cable is disposed at a position exposed when the facing portion is detached from the upper unit.