Non-woven fabric, and oil-water separating filter and oil-water separating method

An oil-water separating filter having a permeability to oil and a non-permeability to water, which comprises a nonwoven fabric made of a melt-blown fiber having a single filament denier of 0.005 to 2.0,[5.55 x 10-3-2,22 dtex] said nonwoven fabric having a fiber packing ratio of 10 to 50% and a water pressure resistance index of 400 to 2,000 mmH2O.