A winding apparatus for sheet-shaped molding material wherein slippage in the width direction can be prevented when the sheet-shaped molding material is wound around a winding core tube, because side plates are detachably mounted on both ends in the axial direction of the winding core tube. Thus, the slippage during the winding operation can be prevented, so that the weight of the molding material being wound can be increased, whereby a thick, wide thick molding compound can be rolled.