A facile and non-distractive method for estimating thermal emissivity of solid polymers based on ATR-FT-IR method was newly developed. This method is applicable to thick and non-transparent samples without using blackbody furnace. The thermal emissivity estimated by this method is consistent with the reference values obtained using blackbody furnace. The ATR-IR method enables to estimate thermal emissivity of polymer materials having arbitrary shapes not only bulk and films but also forms and fabrics.