Manufacturing method of glass forming body and forming die

The present invention provides a manufacturing method of glass formed body and a forming die which make it possible to sufficiently fill a glass material in the forming die and manufacture a glass formed body having a desired shape. The manufacturing method of glass formed body includes: heating a plate-shaped glass material; pressing the heated plate-shaped glass material by the forming die; and cooling and solidifying the glass material transferred shapes of forming surfaces of the forming die by the pressing, wherein planar-view contour shapes of the forming surfaces are non-circular, a gap formed by the forming surfaces is formed so as to become wider from an inner side toward an outer side of the forming surfaces, and pressure distribution occurring in the plate-shaped glass material in the pressing is uniform in a contour region of each of the forming surfaces.