A releasing agent applicator for a toner fixing apparatus including a hot fixing roller and an elastic pressing roller between which toner, transferred onto copying paper, is fixed. It includes a heat resistant felt for holding a releasing agent. A porous polymer membrane is disposed between the felt and the fixing roller. A heat resistant polymer film is thermally fused between the felt and the membrane to bond the membrane to the felt except that portion of the membrane which is brought into contact with the fixing roller. The felt is impregnated with releasing agent and that portion of the membrane without the film may be brought into contact with the fixing roller to allow the releasing agent to be applied to the fixing roller.