A hinge device which rotatably connects a display to a keyboard part comprised of a hinge pivot member which attaches the keyboard part and a bracket which is attached to the display and holds the hinge pivot member and of a hinge cover, wherein if making the bracket hold the hinge pivot member, then attaching the hinge cover to the pivot of the hinge pivot member and making it slide in the axial direction to engage it with the housing of the display part and attaching the front cover to the display part in this state, a projecting part which is provided at the front end part of the front cover is inserted in the hinge cover and return of the hinge cover in the axial direction is prevented, so the front cover and hinge cover can be simply removed at the time of maintenance of the display part.