Method of making three-dimensional object

The invention relates to a method of making a three-dimensional object, comprising the steps of: (a) forming a powder material layer (10) of inorganic material; (b) irradiating an optical beam (L) on a predetermined portion of the powder material layer (10) to form a first sintered layer (11) and integrate the first sintered layer (11) with a second sintered layer (11) just below the first sintered layer (11); (c) repeating the steps (a) and (b) to form a sintered block (B) united with a plurality of the first and second sintered layers (11), the sides of the sintered block (B) including a concave portion (g); (d) removing an excess portion (17) from a surface of the sintered block (B); and (e) repeating the steps (c) and (d) with respect to the sintered block (B) from which the excess portion (17) is removed, in order to make a target shape of a three-dimensional object united with a plurality of the sintered blocks (B).