The present invention performs special heat treatment on a polymer film in a temperature range from (i) a lower limit to temperature rise being equal to or higher than a starting temperature of thermal decomposition of the polymer film, i.e., which is a temperature observed at an early stage of the thermal decomposition of the polymer film, to (ii) an upper limit to temperature rise being equal to or lower than an intermediate temperature of thermal decomposition of the polymer film. This reduces foaming in the film during graphitization treatment following the special heat treatment. Thus, even with a higher heating rate for graphitization, it is possible to produce a graphite film having good quality.