To simplify the whole constitution of a circulation type solid processing device, and to provide a compact constitution.

In this circulation type solid processing device 1, a crushing part to crush solids, an agitating part to agitate the crushed solids with liquid, and a bubbling part to accelerate chemical decomposition of the solids are provide in a first processing tank A, so that the solids are mechanically and chemically decomposed in the first processing tank A, and a load on a second processing tank and on can be minimized. The second processing tank B is composed in such a simple constitution that a sorting part 4 to sort the sizes of the solids is provided, and a third processing tank C is composed in such a constitution as to comprise a filtration part 5 to filter the liquid, so the filtered liquid is temporarily stored in a storage tank D to be reused as solid decomposing water in the device, thereby the whole circulation type solid processing device can be of an extremely simple and compact structure.