A thermally strippable double faced adhesive sheet comprising a substrate, a thermally strippable pressure-sensitive adhesive layer (A) arranged on one side of the substrate, and a pressure-sensitive adhesive layer (B) arranged on the other side of the substrate, in which the substrate comprises a porous substrate. The porous substrate preferably has a density of 0.9 g/cm3 or less and a tensile elastic modulus of 20 MPa or less. The substrate may comprise a laminate of the porous substrate and a non-porous substrate. Exemplary usable adhesives for the pressure-sensitive adhesive layer (B) include pressure-sensitive adhesives, ultraviolet-curable pressure-sensitive adhesives, thermally strippable pressure-sensitive adhesives, thermoplastic pressure-sensitive adhesives, and thermosetting pressure-sensitive adhesives.