A low aspect ratio tokamak device has been designed and constructed in University of Tokyo. A cylindrical vacuum vessel is employed. The vessel is divided toroidally into two parts insulated each other. In the vessel, central core composed of ohmic coils and a part of toroidal coils is installed. The aluminum shell is installed to keep the vertical and horizontal equilibrium of the plasma. As the result of several efforts to lower the aspect ratio, the predicted minimum value of the aspect ratio reaches less than 1.2. The predicted advantage of low aspect ratio tokamaks is verified by simulation. The analysis of MHD activities and fluctuations will be carried out, after the assembly is completed.