Abstract: There is provided a method for manufacturing a three-dimensional shaped object by alternate repetition of a powder-layer forming and a solidified-layer forming, including: (i) forming a solidified layer by irradiating a predetermined portion of a powder layer with a light beam, thereby allowing a sintering of the powder in the predetermined portion or a melting and subsequent solidification of the powder; and (ii) forming another solidified layer by newly forming a powder layer on the formed solidified layer, followed by an irradiation of a predetermined portion of the newly formed powder layer with the light beam. The plurality of the solidified portions of the powder layers overlap each other, and after a formation of a first solidified portion, at least both main edge regions of the first solidified portion are irradiated with the light beam.