A three-dimensional shaping method includes a molded body forming step of forming a molded body having a plurality of projection portions using a material containing a powder and a binder, a supporting step of supporting the molded body by a support having groove portions at positions configured to insert each of the projection portions in a state where the plurality of projection portions are inserted into the groove portions, and a sintering step of sintering the powder by heating the molded body in a state of being supported by the support, wherein the groove portion is extended from an insertion position of the projection portion in a specified direction that specifies a direction of shrinkage of the molded body by performing the sintering step.