To provide a high performance fire retardant filter for collecting dust by passing air through pleated glass filter paper from the internal cavity part of a cylindrical filter to allow the air to flow in the outer peripheral direction of the cylindrical filter.

The fire retardant filter comprises the cylindrical filter 30, which is formed by holding both surfaces of glass filter paper 20 having a high performance air filter (HEPA) between reticulated layers comprising an ethylene/tetrafluoroethylene copolymer 10 being fluoroplastics to press and reinforce the glass filter paper and folding the reinforced glass filter paper into a pleated shape to form the same into a cylindrical shape, and a lid 33 having a hole 34 provided to the center thereof and a lid 32 provided with no hole, both of which are made of SUS 304 and respectively bonded to both ends of the cylindrical filter.