Provided is a pressure-sensitive adhesive which has sufficient adhesive force and is reduced in high-temperature strain. A pressure-sensitive adhesive tape including said pressure-sensitive adhesive is provided. A film substrate including said pressure-sensitive adhesive is provided. Furthermore provided is a pressure-sensitive adhesive film which has sufficient adhesive force and is reduced in high-temperature strain. A pressure-sensitive adhesive tape comprising said pressure-sensitive adhesive film is provided. A film substrate including said pressure-sensitive adhesive film is provided. The pressure-sensitive adhesive of the present invention has an adhesive force in application to the surface of a polyimide film of 1 N or greater and has a storage modulus G' at 160ºC of 1×105 Pa or greater. The pressure-sensitive adhesive film of the present invention has an adhesive force in application to the surface of a polyimide film of 1 N or greater, has a storage modulus G' at 160ºC of 1×104 Pa or greater, an
