To provide a filter medium for a high performance air filter which solves the problem that a conventional glass fiber filter medium is fragile due to its brittleness and difficult to be disposed of and the problem that the particle collection rate of a conventional electret filter medium is unstable, and the high performance air filter using the filter medium.

The filter medium for the high performance air filter, which has the content of organic fibers of 75-89 wt.% by wet paper making is tough and flexible, has a stable particle collection rate, and is suitable for incineration disposal, and the high performance air filter using the filter medium are obtained.