To upgrade the water barrier performance and reliability of the water barrier wall by a water stop sheet.

In the water barrier wall 1 with a water stop sheet 3 installed in a groove 2 formed underground, a double sheet is used as the water stop sheet 3 and is filled with a water permeable material 5 internally. Further, the level of water inside the double sheet is always kept lower or higher than that of water of the surroundings. In addition, a perforated pipe is arranged in the double sheet the internal level of water of the double sheet is kept lower than the surroundings by draining the water from the double sheet through the perforated pipe. Alternatively, the level of water is kept higher than that of the surroundings by injecting the water into the double sheet through the perforated pipe.