To properly crush a plasterboard and efficiently separate plaster pieces from fragments of paper, cloth or the like.

A plasterboard crusher 100 is disclosed comprising a feeding section 10, crushing section 20, driving section 30, supporting section 40, and accumulating sections 49, 49. The crushing section 20 includes: an outer cylinder part 21 of a bottomed cylindrical shape; an inner cylinder part 22 which is coaxially arranged inside the outer cylinder part 21 and which is composed of a cylindrical meshed wall part 22a having an opening on both ends, with one end penetrating the bottom 21a of the outer cylinder part 21 and becoming a discharging end of the fragments 97 of the plasterboard pieces 99, and with the other end becoming an feeding end of the plasterboard pieces 99; a helical conveyance wall 23 which is helically formed around a rotary shaft P in a space 29 between the outer and inner cylinder parts 21, 22; and a plurality of rods 24 which crush the plasterboard pieces 99 inside the inner cylinder part 22. The plaster pieces 98 are crushed in sizes passing the wall part 22a and discharged from an opening 21c through the helical conveyance wall 23, while the fragments 97 are discharged from an opening 22b.