To produce the cartridge filter containing the filter material remarkable in antibacterial function to Escherichia coli, etc.

The antibacterial filter material 9 constituted by adding a suitable amount of water to a mixture of an oyster shell fine powder, zeolite and sodium silicate in suitable compound ratio, kneading the mixture, burning the knead matter at high temp., then granulating the burned matter is packed at a gap S between a core 2 forming an inner wall 1a of a hollow resin cylindrical body 1 and a hot-melt nonwoven fabric 3 forming an outer wall 1b with a certain interval, and its outer layer part is melt-stuck thermally with the hot- melt nonwoven fabric 3, moreover, the whole periphery is wrapped with a resin protective net 4 and an end cap 5 is fitted at both ends of the cylindrical body 1.