Pfa molded body with excellent blister resistance and method of controlling occurrence of blisters in pfa molded body

A molded body with a hollow portion comprising tetrafluoroethylene and perfluoro(alkyl vinyl ether) copolymer obtained by heat treating a melt-molded body with a hollow portion comprising tetrafluoroethylene and perfluoro(alkyl vinyl ether) copolymer containing 3 to 50 weight % of perfluoro(alkyl vinyl ether) and having a melt flow rate of 0.1 to 100 g/10 min when measured with a load of 5 kg and a measurement temperature of 372±0.1° C. in accordance with ASTM D1238, wherein said heat treating is performed at a temperature of from 130° C. below the melting point of said copolymer to the melting point of said copolymer, and wherein said molded body has a blister presence rate of 50% or less as calculated by the equation:

• blister presence rate=number of blisters in a heat treated molded body/number of blisters in an equivalent molded body that has not been heat treated.