A hinge device for use in a foldable device is provided which allows the cover member to be pivoted clockwise and counterclockwise so that the cover member can be used in a variety of ways and also has an excellent functionality. A cellphone using such a hinge device is also provided. A hinge device connecting a body member 13 and a cover member 12 comprises: open-close hinge units 3, 4 to open and close the cover member 12 and to hold the open cover member 12 at a first open position where a cellphone operation can be performed; and a pivotal hinge unit 4 secured to the body member 13 and activated when the cover member 12 is opened beyond the first open position, the pivotal hinge unit 4 being adapted to pivot the cover member 12 clockwise or counterclockwise and to hold the cover member 12 at a pivotal position 90 or 180 degrees clockwise or counterclockwise from the body member.