NOVELTY - Production of pyromellitic dianhydride involves dissolving a raw material of pyromellitic dianhydride in an acetic acid solvent, preparing a raw material solution, recrystallizing the pyromellitic dianhydride in the prepared raw material solution, separating the acetic acid solvent, preparing a precursor pyromellitic dianhydride, performing a degassing treatment in the precursor pyromellitic dianhydride by stirring the precursor pyromellitic dianhydride in a fluidized state and heating in reduced pressure conditions, and taking-out the pyromellitic dianhydride.    USE - Production of pyromellitic dianhydride used for forming semiconductor film used in solar cell.    ADVANTAGE - The method enables production of pyromellitic dianhydride with high purity by evaporating at a stable concentration for a long period of time, without causing an uneven distribution, by simple process, which provides semiconductor film with excellent insulation property and blackening-proof property.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) apparatus for supplying pyromellitic dianhydride, which consists of a sample placing unit for placing a sample tray in which the pyromellitic dianhydride is charged, a supplying unit for supplying a carrier gas, a dispersing unit for dispersing the supplied carrier gas, and an outputting unit for outputting gaseous pyromellitic dianhydride prepared in the sample placing unit. The powder and granular pyromellitic dianhydride placed in sample placing unit is evaporated in predetermined temperature conditions, dispersed in atmospheric pressure or reduced pressure conditions of carrier gas atmosphere entrained by the carrier gas, and outputted as gaseous pyromellitic dianhydride; and    (2) supply of pyromellitic dianhydride, which involves providing powder and granular pyromellitic dianhydride, placing powder and granular pyromellitic dianhydride in sample placing unit, supplying carrier gas to the supplying unit, heating sample placing unit in carrier gas atmosphere to temperature conditions corresponding to a desired vapor pressure of pyromellitic dianhydride, and outputting gaseous pyromellitic dianhydride entrained by the supplied carrier gas in desired predetermined pressure conditions.