PURPOSE: To produce a synthetic fiber solid staple having a high strength against tension or flexure in an arbitrary direction by layering plural sheets of fiber material for lamination so that the fiber directions of the respective sheets may be perpendicularly intersected and applying a thermocompression treatment thereto.

CONSTITUTION: Synthetic fiber raw staples are supplied from the first, second and third hoppers 21, 31 and 41 respectively storing the raw staples to the first, second and third combing units 22, 32 and 42 to form a fabric-state combed textile material. The formed fabric-state combed fiber materials are subsequently supplied respectively to the first, second and third laminating units 23, 33 and 43, put in layers through a pendulum-type distributor, allowed to pass through respective compacting units and put in layers by an automatic conveyor 5 so that the fiber directions of the respective first, second and third fiber material sheets for lamination may be perpendicularly intersected. The layered materials are then conveyed to a compression bonding unit 6 so as to be compressed, subsequently monolithically heat-treated in a heat-treating unit 7, cooled and cut into a prescribed shape by a cutter 8. The shaped material is then sent to a surface winder 9, thus producing the objective synthetic fiber solid staple.