To provide a low odor composting treatment method with which occurrence of offensive odor is suppressed by a two-stage system comprising fermentation performed in a low temperature region while suppressing the occurrence of the offensive odor and fermentation performed in a high temperature region, and by which the fermentation can be completely performed.

In the composting treatment method comprising inoculating a single microorganism or a plurality of microorganisms to household waste materials or animal and plant residues, then proliferating the microorganism, performing fermentation, and decomposing the waste materials or the residues, a primary treatment includes a primary fermentation process using a microorganism having a deodorizing function, and a secondary treatment includes a secondary fermentation process performed at a temperature higher than that of the primary fermentation process by using a microorganism having a composting promoting function.