To provide a circulating toilet using a compound fermentation method in a limited space.

The circulating toilet based on the compound fermentation method is constituted of a toilet seat 1, a fermenter 2, a fermentation composition tank 3, a fermentation precipitator 4, and a composition tank 5. The fermenter and the fermentation composition tank 3 treat excrement from the toilet seat 1. The fermentation precipitator 4 divides a liquefied object discharged from the fermentation composition tank into a bacillus bed and water and returns the bacillus bed to the fermenter. The composition tank 5 performs the contact aeration of the water discharged from the fermentation precipitator and circulates it as water used for flushing. The fermentation composition tank, the fermentation precipitator, and the composition tank are arranged directly above the fermenter 2 having a shape which is wide in the horizontal direction and shallow in the vertical direction, and the fermenter mainly performs aerobic fermentation. The fermentation composition tank 3, the fermentation precipitator 4, and the composition tank initiate fermentation which becomes more anaerobic as it goes to the downstream side, and have shapes which are narrow in the horizontal direction and deep in the vertical direction.