This invention relates to a bag filter having a tubular section, one closed end and one open end, the tubular section having a nonwoven felt comprising an intimate fiber blend of 50 to 80 parts by weight meta-aramid fiber and 20 to 50 parts by weight acrylic fiber, based on the total weight of meta-aramid and acrylic fibers in the felt, wherein the acrylic fiber has an equal or lower denier per filament than the meta-aramid fiber.