The invention provides a TFE polymer capable of providing stretched materials excellent in membrane homogeneity. The present invention is related to a tetrafluoroethylene polymer having stretchability and non-melt-processability and having a standard specific gravity of 2.140 to 2.165, wherein, with regard to the heat-of-fusion curve obtained by subjecting the tetrafluoroethylene polymer in the form of an unbaked polymer to be measured having no history of being heated to a temperature of 300.degree. C. or higher to differential scanning calorimetry at a programming rate of 2.degree. C./minute, the ratio between the amount of heat, S.sub.2 mJ/mg, absorbed within the temperature range of from the temperature T.sub.0.degree. C., which is lower by 2.5.degree. C. than the temperature T.sub.p.degree. C. corresponding to the minimum point on the curve (provided that 340.ltoreq.T.sub.p.ltoreq.345), up to 350.degree. C., and the amount of heat, S.sub.1 mJ/mg, absorbed within the temperature range of from 320.degree. C. up to the above-mentioned T.sub.0.degree. C., namely the ratio [S.sub.2/S.sub.1], is not lower than 0.90.