Abstract: To use cooking oil repeatedly for a long time while maintaining quality of the cooking oil in a good condition, a cooking oil filter apparatus according to this invention filters the cooking oil collected from a fryer in using a filtering material. A fragment of granite porphyry containing amphibole is used as the filtering material. The granite porphyry containing the amphibole indicates a good antioxidant effect against the cooking oil, and the cooking oil is recycled upon contact with the granite porphyry, thereby prevented from degrading. As a structure, for example, the apparatus has a filter cartridge containing the fragment of the granite porphyry containing the amphibole, in which a basket and a paper filter respectively in a mesh form are disposed on the filter cartridge.