An information terminal device includes: a first housing that has a first operating unit on a face on one side thereof; a hinge member that is designed to rotate about a first axis, with respect to the first housing; a second housing that has a second operating unit on a face on one side thereof, is provided on one side of the first housing, slides in the direction of a second axis perpendicular to the first axis, and transits between a state where the second housing covers the first operating unit and a state where the first operating unit is exposed, the second housing restricting rotation of the hinge member through contact with the first housing when the second housing is in the covering state; and a third housing that has a display unit on a face on one side thereof, is provided on one side of the second housing, slides in the direction of the first axis, and transits between a state where the third housing covers the second operating unit and a state where the second operating unit is exposed.