[en] An Inner Drift Chamber (IDC) has been constructed for the TOPAZ e⁺e^- experiment at TRISTAN. The IDC has a cylindrical shape with dimensions of 20 cm in inner diameter, 60 cm in outer diameter and 150 cm long. The IDC is equipped with 1024 anode wires grouped into 10 layers. For the position readout along the anode wires, eight delay-line layers are placed on coaxial cylinders made of Normex honeycomb. The chamber is operated with a gas mixture of Ar(89 %)/CO₂(10 %)/CH₄(1 %) at an atmospheric pressure. In this paper, details of the mechanical structure and the fabrication procedures are described. (author)