To provide a waste treatment system attaining the various use and rational utilization of a waste treatment vehicle by smoothly and efficiently shredding papers and a large amount of waste made of synthetic resin on a vehicle or indoors/outdoors and recovering them.

A waste treatment system includes a cutting chamber 22 having a shredder 24 for shredding waste, in a waste treatment space partitioning the periphery, and a conveying part for conveying out shredded pieces 28 to a shredded piece storage chamber 25, wherein the stored shredded pieces 28 can be taken out. A retaining part 30 that can retain a part of the shredded pieces 28, and a communicating passage 31 allowing downward drop, are adjacently arranged at the upper part of a moving passage 29 of the shredded pieces 28. The retaining part 30 is provided with a rotating shaft 32 mounted with a helical fin 33 so that the retained shredded pieces 28 can be conveyed out to the communicating passage 31 side. A lower part of the communicating passage 31 is provided with a rotating shaft 34 mounted with a helical fin 35, and the shredded pieces 28 can be conveyed out to the shredded piece storage chamber side 25 through the rotating shaft 34 or the helical fin 35 below.