PURPOSE: To prevent the escape or dilution of a grout by a method in which an anchor material whose periphery is provided with a shielding sheet of a dimension enough to cover the majority of the inside of a hole is penetrated into the hole and then a grout is packed into the sheet.

CONSTITUTION: An anchor hole 4 is excavated, and an anchor material 1, e.g., cable, etc., whose periphery is provided with a shielding sheet 3 of vinyls, etc., having excellent water proofness and excellent flexibility, is penetrated into the hole 4. A grout, e.g., cement mortar, etc., is sent through the tip of a hose 2 integrally set to the anchor material 1 and packed into the sheet 3 provided to the periphery of the anchor material 1 so that the sheet 3 is pushed and expanded by the cement mortar to contact with the wall of the hole 3. The leakage of the grout can be completely prevented by the sheep 3 and also the escape or dilution of the grout by ground water or excavating water can be prevented.