PURPOSE: To stabilize the opening/closing of a lid, and improve the controllability by a method wherein a first hinge part is pivotally supported on a surface of a lid on a box body side, which is rotatably attached on the box body part of an electronic book, etc., and also, a second hinge part is pivotally supported in the box body, and the other end of the second hinge part is pivotally fixed to the other end of the first hinge part.

CONSTITUTION: A hinge fulcrum metal fitting 17 is provided on the lower surface of a keyboard unit 15 of an electronic apparatus, and also, a hinge fulcrum metal fitting 22 is provided on the bottom of a lower case 13 respectively. Then, one end of a hinge fitting 18 is pivotally fixed 19 on the fitting 17, and one end of a hinge fitting 20 is installed 23 on the fitting 22. Then, the other ends of these hinge fittings 18, 20 are pivotally fixed by a pin 21 to each other. Then, by a spring member 24 wherein one end is attached to the lower surface of the unit 15, and the other end being bent into an approx. hook shape is attached to the hinge fulcrum metal fitting 18, a lid is energized downward under a condition wherein the keyboard unit 15 is closed. Also, under a condition wherein the keyboard unit 15 is opened, the spring member 24 separates from the pin 21 to keep the keyboard unit 15 under the open condition.