NOVELTY - Temporary molding of raw material powder containing silica particles is carried out to predetermined shape with respect to inner wall (102) of outer die frame (101), to form silica-substrate temporary molded material. A mixed gas containing oxygen gas and inert gas is supplied from inner side of temporary silica-substrate molded material. The inner side of temporary molded material is heated by discharge heat-melting process to form a silica substrate (51), to obtain silica container.    USE - Manufacture of silica container (claimed) used for melting metallic silicon for solar cell, and manufacturing silicon crystal.    ADVANTAGE - The method enables economical manufacture of silica container having excellent dimensional stability and thermal deformation resistance, with high yield.    DETAILED DESCRIPTION - A raw material powder containing silica particles is prepared, and the pressure-reduction hole (103) is distributed and formed in inner wall of die. The raw material powder is introduced to inner wall of an outer die frame, and the outer die frame is rotated. Temporary molding of raw material powder is carried out to predetermined shape with respect to inner wall of outer die frame, to form temporary molded material of silica substrate. A mixed gas containing oxygen gas and inert gas having predetermined dew point temperature or less is supplied from inner side of temporary molded material of silica substrate. The gas in the outer die frame is ventilated, and the humidity of the inside of outer die frame is adjusted. The temporary molded material of silica substrate is pressure-reduced and degassed from outer peripheral side. The inner side of temporary molded material of silica substrate is heated by discharge heat-melting process to form a silica substrate, to obtain silica container. The inner peripheral portion of temporary molded material of silica substrate comprises molten-glass material, and outer peripheral portion of temporary molded material of silica substrate comprises sintered compact.    DESCRIPTION OF DRAWING(S) - The drawing shows the sectional view of the silica container.    Silica substrate (51)    Outer die frame (101)    Inner wall (102)    Hole (103)    Carbon electrode (212)