The invention provides a pressure-sensitive adhesive tape for the protection of photo masks which is not deteriorated in peelability even after it has been repeatedly used in a state adhering closely to photo resists having pressure-sensitive adhesion properties and thus permits repeated use. A pressure-sensitive adhesive tape for the protection of photo masks which comprises a transparent substrate film or sheet (A), a pressure-sensitive adhesive layer (B) formed on one side of the film or sheet (A), and a face layer (C) formed on the other side thereof, wherein the face layer (C) is made ofa specific product obtained by curing a mixture comprising both an isocyanate silane (x) and a siloxane (y) having a hydroxyl group at the end.