AIR FILTER MATERIAL, FILTER PACK, AND AIR FILTER UNIT

Provided are a filter medium for an air filter, a filter pack, and an air filter unit capable of being extended life even when composed of embossable material. The filter medium (1) has a tensile elongation of 10% or greater, and includes a main collection layer (30) having a filing rate of 5% to 15%, a thickness of 0.35 mm to 0.70 mm, and a peak in a fiber diameter distribution at less than 1.0 µm and a peak at 1.0 µm or greater. An average fiber diameter of small fiber diameters of less than 1.0 µm is from 0.1 µm to less than 0.8 µm, and an average fiber diameter of large fiber diameters of 1.0 µm or greater is from 1.2 µm to less than 3.0 µm. A volume ratio of the fibers having the small fiber diameter to the fibers having the large fiber diameter is from 30:70 to 80:20.