To provide an extrusion T die apparatus capable of obtaining a resin film having a homogeneous thickness by measuring the temperature distribution or thickness distribution of a molten resin film extruded from the lip distal end of an extrusion T die along the die width direction (longitudinal direction), by controlling the temperature of a heater configured on the die based on the feedback of the measurement data into the heater, and, as a result, by controlling the temperature distribution or thickness distribution of the molten resin film immediately after the extrusion thereof from the die.

The provided extrusion T die apparatus is an extrusion T die apparatus for feeding a molten resin into a T die having a slit-shaped aperture, and then extruding it as a film, and comprises the T die, a heating means, a temperature measurement means, a film thickness measurement means, and a temperature control means.