To provide a culture material for promoting the high concentration proliferation or sporulation of a bacillus bacterium, and to provide a waste water-treating method using the same.

This culture material is characterized by adding an iron compound to the powder of a siliceous ore and a clay mineral. The culture material is characterized by adding iron sulfate, iron polysulfate, an iron salt or iron sulfate, an iron salt-mixed material to the powder of a siliceous ore and clay mineral. The culture material is characterized by mixing the culture material with a bacillus bacterium and controlling a waste water-treating operation and the bacterial cells. The waste water-treating method is characterized by promoting the high concentration proliferation or high concentration sporulation of the bacillus bacterium participating in a bacillus bacterium waste water treatment using the culture material.