To provide a heat-resistant filter medium with superior size stability, for filtering dust contained in high-temperature exhaust gas with a high collection rate, with superior tangling property of fibers composing felt, reducing falling of fibers due to a needle punch process at felt forming time and impact at dedusting time, and generation amount of white pill-like fiber chips in the needle punch process, and usable at a higher operation temperature region than a heat-resistant filter comprising 100% PPS fiber.

This heat-resistant filter medium contains heat-resistant organic fiber and glass fiber having crimps. The heat-resistant organic fiber contains at least polyphenylene sulfide fiber. A bag filter is composed of such a heat-resistant filter medium as a filter cloth.