A three-dimensional shaping method in which after formation of a powder layer with a predetermined thickness, a step for sintering the powder layer by an optical beam is performed at a predetermined number of times and, thereafter, a periphery thereof is cut, comprising that a control system stores in advance a fine region at coordinate positions in a horizontal direction and a height direction in which a cross-sectional area or a mean diameter of an expected sintered part in a horizontal direction is equal to or less than a predetermined extent corresponding to a cause for forming a raised sintered portion on each layer, and when the fine region at the coordinate positions is present on an individual layer to be sintered, the control system temporarily stocks the region at the coordinate positions, and also after sintering of the layer concerned is completed, at an intermediate height position between the position of the surface on which the sintering has been completed and the lowest position of a powder supplying blade moving in the horizontal direction for forming a powder layer on a next layer on the upper side of the layer concerned, a rotating cutting tool travels around the fine region at the coordinate positions in the horizontal direction and an outer peripheral vicinity thereof according to instructions of the control system, thereby, in the case of a raised sintered portion forming on the upper side of the region at the coordinate positions, the rotating cutting tool cuts the raised sintered portion entirely or partially with detecting in advance the cause for forming a raised sintered portion on each layer in a stage before the formation of a next layer positioned on the upper side of the layer concerned, or that on an individual layer to be sintered, a control system determines the cross-sectional area or the mean diameter and when the cross-sectional area or the mean diameter is determined to be equal to or less than a predetermined extent corresponding to the cause for forming a raised sintered portion on each layer, the control system temporarily stocks coordinate positions in the horizontal direction and the height direction at the fine region in which the cross-sectional area or mean diameter has been determined to be equal to or less than the predetermined extent, and also after sintering of the layer concerned is completed, at the intermediate height position between the position of the surface on which the sintering has been completed and the lowest position of a powder supplying blade moving in the horizontal direction for forming the powder layer on the next layer on the upper side of the layer concerned, the rotating cutting tool travels around the region at the coordinate positions in the horizontal direction and an outer peripheral vicinity thereof according to instructions of the control system, thereby, in the case of the raised sintered portion forming on the upper side of the region at the coordinate position, the rotating cutting tool cuts the raised sintered portion entirely or partially with detecting in advance the cause for forming a raised sintered portion on each layer in a stage before the formation of a next layer positioned on the upper side of the layer concerned.