To obtain a nonwoven fabric hardly causing surface fuzzes, excellent in fouling preventing and removing properties and suitable as a material for high-temperature bag filters or various filters by partially thermally fusing a web of fluororesin-based fibers such as of a PFA resin or PTFE resin.

This nonwoven fabric suitable for various filters, etc., is obtained by opening fluororesin-based fibers such as of a PFA resin or a PTFE resin, forming a web, then carrying out the partial thermal fusing treatment with a hot press equipped with a metallic mold heating plate and thereby incompletely fusing the fibers in thermally fused parts so as to retain the shape thereof.