To provide an apparatus for methane fermentation treatment capable of reducing the load applied to a deodorizing device at the time of deodorization of a malodor produced by the grinding treatment of organic waste and capable of miniaturizing the deodorizing device.

In the apparatus for methane fermentation treatment equipped with a pretreatment tank 1 for grinding organic waste to classify the same, a methane fermentation tank 3 for subjecting the organic waste supplied from the pretreatment tank 1 to methane fermentation and a biological reaction tank 4 for cleaninging the methane fermentation waste liquid discharging from the methane fermentation tank 3, a means for sucking the air in the pretreatment tank 1 to supply it to the biological reaction tank 4 as aeration air is provided.