| 摘要 |
<p>Gas permeable base materials (3, 4) are provided at least on one surface of a porous film (2) of polytetrafluoroethylene (PTFE) to provide a filter medium, which is efficient and reasonable because a maximum amount of organic substances detected from the filter medium is 3 ng or less per 1 g of the filter medium, and an air filter unit using the filter medium.</p> |
