The purpose of this study was to analyze conductive convective and radiative heat transfer characteristics of nonwovens. Contribution of the air content to the conductive convective and radiative heat transfer of the nonwovens were studied by measuring thermal conductance at atmospheric and low air pressure. The results obtained were as follows; 1) As thickness of air layer increased, overall heat transfer was decreased by reducing conductive and radiative heat trasfer. 2) The conductive and convective heat trasfer by air were in the rangs of 79--89% of overall heat transfer. 3) As thickness of nonwoven increased for a given solidity, overall heat trasfer was decresed by increasing total thickness of air layer and by reducing conductive and radiative heat transfer. 4) For a given weight, increasing thickness is more effective than increasing solidity.