An adhesive substrate is disclosed, which includes a base substrate and a heat-resistant elastomer layer formed on the base substrate, wherein the base substrate is flexible and has a thickness of 0.2 mm or more and 2 mm or less, wherein the adhesive substrate is used as part of a method for physically separating an object that has been held immovable in such a manner that the object has been adhered to by the heat-resistant elastomer layer and the object is anchored from the upper side, and wherein by starting to physically separate the end portion of the adhesive substrate downward the object is able to be separated.