To provide a hinge structure capable of giving sufficient strength in a simple manufacturing process without using an axial pin.

A hinge structure consists of two fitting members 2 paired in line, each having a protruded portion 1a, a recessed portions 1b and an opening portion 1c on the side periphery thereof. The opening portion 1c communicates the recessed portion 1b with the outside of the recessed portion 1b in the direction perpendicular to the extending direction of the fitting member 2. The protruded portion 1a and the recessed portion 1b are shaped in axial symmetry in the extending direction of the fitting member 2. A fitting element is formed with parts having each one of the protruded portion 1a, the recessed portion 1b and the opening portion 1c provided for the fitting member 2, as one unit. The protruded portions 1a of both fitting elements 1 are mutually fitted to the recessed portion 1b of the other fitting element 1, so that two hinge pieces 3 are assembled.