The surface of the fiber of the fiber assembly is roughened, the surface area of the fiber per unit volume is large, the contact area with the fine particles in the air can be increased, and the surface of the fiber of the fiber assembly is PM2.5. Since the particles are easy to contact and adhere to, and the force to adsorb the particles is strong, the particles can be collected without escaping, and the collected particles can be held securely, and even if it is thin, processing of dust and particles In addition to excellent collection efficiency and certainty of target substances, it also has excellent shape stability and processability, as well as excellent corrosion resistance, durability, and quality stability. Provide a filter for air cleaning that can be removed by suction with a vacuum cleaner, and has excellent maintainability and environmental protection. A fiber assembly formed of non-woven fabric with aluminum or aluminum alloy fibers, a shape-retaining member having a plurality of holes and covered on both planes of the fiber assembly, and at least upstream of the fiber assembly And a recess formed by roughening the surface of the fiber.繊維集合体の繊維の表面が粗面化されて、単位体積当たりの繊維の表面積が大きく、空気中の微粒子との接触面積を増大させることができ、繊維集合体の繊維の表面にＰＭ２．５のような微粒子が接触して付着し易く、微粒子を吸着する力が強いため、微粒子を逃さずに捕集できると共に、捕集した微粒子を確実に保持でき、薄くても塵埃や微粒子等の処理対象物質の捕集の効率性、確実性に優れるだけでなく、形状の安定性、加工性に優れ、また耐食性、耐久性、品質の安定性にも優れ、吸着した処理対象物質を洗浄したり、掃除機で吸引したりして取除くことができ、メンテナンス性、環境保護性に優れる空気清浄用フィルタの提供。 アルミニウム製又はアルミニウム合金製の繊維で不織布状に形成された繊維集合体と、複数の孔部を有し繊維集合体の両平面に覆設された保形部材と、少なくとも繊維集合体の上流側の繊維の表面を粗面化して形成された凹部と、を備えている。
