To improve execution by providing a spacer member for holding main wall members in a partition wall space formed by a pair of the main wall members and a pair of size wall members at a specified interval and constituting the main wall members by a screen.

A spacer member 9 for holding main wall members 2, 2' in a partition wall space 4 formed by a pair of the main wall members and a pair of side wall members 3, 3' at a specified interval is provided, and a partition wall body screen 1 is constituted. However, the main wall member 2 is constituted with a plate-like wedge wire screen 5. After both opening ends of the screen 1 is closed with a cover, a plurality of the screen 1 is constructed in a site, and the site of the inside of an enclosure is blocked from an outside ground water layer by making the enclosure, inside ground water of the enclosure is drained in the outside through the screen 5. Thereby the ground water level in the site can be lowered down to a desired level without otherwise constructing any deep well screen.