Structure of partition wall and method for construction partition wall

An object of the invention is to provide a structure of a partition wall to be constructed in a single-runner pattern, which can improve a sound-insulation performance of the wall in middle and high frequency regions.A partition wall (1) has a structure with a wall end portion (1a) butted against another building structure (C,W,1') and exposed to architectural spaces. An end post (10) at the end portion of the wall is constituted from first and second end post elements (11 - 16), which are spaced apart from each other, so that a gap (β,γ) or an isolation zone (42) interrupting a propagation of a solid vibration or insulating a path for propagating the solid vibration is formed between the first and second elements. An interior finishing panel (5,6) for defining the architectural space (R2) on one side of the wall is fixed to the first element (11,13,15) and the interior finishing panel for defining the architectural space (R1) on an opposite side of the wall is fixed to the second element (12,14,16).