To provide a garbage treatment system capable of shortening the treatment time for treatment garbage, enhancing the garbage treatment volume and automatically discharging foreign matter within a crushing/separation device from it, and also to provide devices for the system.

The process using this garbage treatment system comprises crushing garbage with a crushing/separation device, subjecting the crushed garbage to decomposition into water and gaseous carbon dioxide with a treatment device so as to allow the garbage to disappear, separating treated water discharged from the treatment device into a sludge layer, a purified water layer and a water oil layer in a recycle water tank, concurrently, recycling purified water in the purified water layer in the recycle water tank to the crushing/separation device, also recycling sludge in the sludge layer in the recycle water tank to the treatment device, and further, separating waste oil in the waste oil layer in the recycle water tank into oil and waste water with an oil treatment device, wherein, in addition, the crushed garbage with the crushing/separation device is received in an anaerobic tank to remove oil in the crushed garbage, and also, received water in the anaerobic tank is supplied to the treatment device.