A process of producing a three-dimensionally shaped object comprising a layer forming step of forming a powder material having a refractive index n.sub.1 into a layer having a prescribed thickness on a support, a cross-sectional shape forming step of binding the layer of the powder material formed in the foregoing step into a prescribed cross-sectional shape with a binding agent having a refractive index n.sub.2; and repeating these steps successively, wherein n.sub.1 and n.sub.2 satisfy the relationship of -0.1.ltoreq.(n.sub.1-n.sub.2).ltoreq.0.1.