PROBLEM TO BE SOLVED: To provide an adhesive hydrogel having excellent repeating adhesive force without being accompanied by special work such as cleaning.SOLUTION: The adhesive hydrogel is made of a polymer matrix containing water, a polyhydric alcohol, and a polyvinylpyrrolidone having a K value of 25 to 88. The polymer matrix is a copolymer of a polymerizable monomer mixture and a crosslinkable monomer containing (meth)acrylic acid, its derivative or a 4-5C vinyl derivative having two carboxyl groups and (meth)acrylamide or its derivative, and with respect to 100 pts.wt. of the adhesive hydrogel, (meth)acrylic acid, its derivative or a 4-5C vinyl derivative having two carboxyl groups is contained in 2.5 to 22.5 pts.wt., (meth)acrylamide or its derivative is contained in 2.5 to 22.5 pts.wt., and the polyvinylpyrrolidone is contained in 5 to 40 pts.wt.
