To provide a small and inexpensively manufacturable hinge device with a simple structure.

In the hinge device, a device body and a display body are composed so that they can be relatively folded by connecting each attaching cylinder respectively protrudedly provided on an end part of the device body and an end part of the display body and overlapped so as to mutually share an axis in an axial direction by a hinge constituent member incorporated inside each attaching cylinder and having at least a fixed cam, a fixed member, a sliding cam facing the fixed cam and slidably provided so as to rotate together with the fixed member, and an elastic means pressing the sliding cam toward a fixed cam side. By composing a single hinge body by using the hinge constituent member, inserting the hinge body toward the attaching cylinder positioned in an inner side than the attaching cylinder positioned in an outer side, and respectively engaging the fixed cam to one of the attaching cylinders and the fixed member to another, the device body and the display body are connected so that they can be relatively folded and a part of the hinge body is locked to the attaching cylinder positioned in the inner side so that it does not come loose in the axial direction.