Abstract: A hinge apparatus to open and to close an upper member such as an automatic document feeder or an upper cover used in an office machine has an upper hinge fixed on the upper member, a lower hinge fixed at a main body of the office machine, a hinge shaft to rotatably support the upper and lower hinges with respect to each other, and a position-fixing member to fix the upper member in at least one position opened at a predetermined angle by restraining the upper and lower hinges from rotating with respect to each other when the upper member is opened. The position fixing member has a first fixing part to restrain the rotation of the upper and lower hinges from a direction perpendicular to an axis of the hinge shaft and a second fixing part to restrain the rotation of the upper and lower hinges from an axis direction of the hinge shaft.