The provided ventilation filter is a ventilation filter having a porous membrane the surface of which has been coated by an oil-repelling agent, wherein the porous membrane is a polytetrafluoroethylene stretch porous membrane and the oil-repelling agent contains linear fluorine-containing hydrocarbon groups represented by 1) -R1C5F10CH2C4F9 or 2)-R2C6F13. R1 and R2 are each independently a C1-12 alkylene or phenylene group. Oil repellency is imparted to the ventilation filter without a large reduction in ventilation performance.
