A pressure sensitive adhesive obtained by polymerizing a mixture containing: 1) 100 mass parts of (meth)acrylic monomer comprising 98-50 mass parts of a first monomer selected from an aliphatic (meth)alkyl acrylate having a carbon number of 4-6 and an aliphatic (meth)alkyl acrylate having a carbon number of 7-12, wherein the glass transition temperature of a homo-polymer thereof is -25 degrees C or less; and 2-50 mass parts of a second monomer comprising one or more selected from the group consisting of: an amide group-containing ethylenic unsaturated copolymerizing monomer, a carboxylic group-containing ethylenic unsaturated copolymerizing monomer, an amino group-containing ethylenic unsaturated copolymerizing monomer, a non-tertial alkyl(meth)acrylate wherein the glass transition temperature of a homo-polymer thereof is -25 degrees C or more, and a monomer represented by the chemical structural formula CH 2 =CR 1 COO(R 2 O)nR 3 or CH 2 =CR 1 COOR 4 R 5 (R 1 =methyl or H; R 2 and R 4 = linear or branched alkyl having a carbon number of 1-6; R 3 =methyl, ethyl, or substituted or non-substituted phenyl; R 5 =substituted or non-substituted 4-membered or 5-membered ring containing oxygen; n=1-16); 2) 10-100 mass parts of a block copolymer; 3) 20-100 mass parts of hydrogenated tackifier; and 4) 0.05-1.0 mass parts of a photopolymerization initiator. 1) 100 mass parts of (meth)acrylic monomer comprising 98-50 mass parts of a first monomer selected from an aliphatic (meth)alkyl acrylate having a carbon number of 4-6 and an aliphatic (meth)alkyl acrylate having a carbon number of 7-12, wherein the glass transition temperature of a homo-polymer thereof is -25 degrees C or less; and 2-50 mass parts of a second monomer comprising one or more selected from the group consisting of: an amide group-containing ethylenic unsaturated copolymerizing monomer, a carboxylic group-containing ethylenic unsaturated copolymerizing monomer, an amino group-containing ethylenic unsaturated copolymerizing monomer, a non-tertial alkyl(meth)acrylate wherein the glass transition temperature of a homo-polymer thereof is -25 degrees C or more, and a monomer represented by the chemical structural formula CH 2 =CR 1 COO(R 2 O)nR 3 or CH 2 =CR 1 COOR 4 R 5 (R 1 =methyl or H; R 2 and R 4 = linear or branched alkyl having a carbon number of 1-6; R 3 =methyl, ethyl, or substituted or non-substituted phenyl; R 5 =substituted or non-substituted 4-membered or 5-membered ring containing oxygen; n=1-16); an amide group-containing ethylenic unsaturated copolymerizing monomer, a carboxylic group-containing ethylenic unsaturated copolymerizing monomer, an amino group-containing ethylenic unsaturated copolymerizing monomer, a non-tertial alkyl(meth)acrylate wherein the glass transition temperature of a homo-polymer thereof is -25 degrees C or more, and a monomer represented by the chemical structural formula CH 2 =CR 1 COO(R 2 O)nR 3 or CH 2 =CR 1 COOR 4 R 5 (R 1 =methyl or H; R 2 and R 4 = linear or branched alkyl having a carbon number of 1-6; R 3 =methyl, ethyl, or substituted or non-substituted phenyl; R 5 =substituted or non-substituted 4-membered or 5-membered ring containing oxygen; n=1-16); 2) 10-100 mass parts of a block copolymer; 3) 20-100 mass parts of hydrogenated tackifier; and 4) 0.05-1.0 mass parts of a photopolymerization initiator.