To provide a waste carbonizing method for removing ammonia generated in an organic waste treatment process, self-supporting a heat source for accelerating fermentation and solving a malodorous problem in the livestock industry, especially in the livestock industry developed in a cold district and a pollution problem of rivers or soil.

The waste carbonizing method comprises a dehydration process for separating livestock excretions into highly concentrated wastewater and a solid, a fermentation process for mixing garbage with highly concentrated wastewater to generate biogas and a process for mixing the solid of livestock excretions and the residue after the generation of the biogas to dry and carbonize them.