The invention discloses a half mirror, which comprises, in the stated order, a glass plate, a pressure-sensitive adhesive layer, and a polarized reflection layer having a thickness of 5.0 to 80 [mu]m.The pressure-sensitive adhesive layer has a thickness of 3 to 15 [mu]m and is obtained by ultraviolet curing of a composition comprising an acrylic polymer having a weight-average molecular weight of800,000 to 2 million, a crosslinker, and a silane coupling agent. The total quantity of the crosslinker is 1.0 to 8.0 mass% of the quantity of acrylic polymer, and 80 mass% or more of the crosslinkeris a photocrosslinker.