Comfort is not taken into consideration by users since the protection and strength properties of protective clothing are more important. That results in decreasing the work productivity of workers after a while. In recent years in order to increase the work productivity, many methods have been tried. Basic approaches in these methods are intended to providing comfort inside of clothing. Also, the topic of comfort in protective clothing has been of interest to many researchers. The moisture and evaporation heat with depending on that moisture are provided to reject by using breathable membranes with the aim of increasing comfort inside of protective clothing. This is an important case for regulation of body heat (thermal regulation). On the other hand determinations of thermal insulation properties are important as well as moisture permeability properties of breathable membranes. For this purpose, in this study thermal insulation properties of those membranes which consist of different materials and layers were tested on Alambeta device and the results were compared with graphics. Also it was discussed how those membranes will be able to effect the comfort inside of protective clothing or not. The results showed that breathable membranes and porous structures which are begun to use in designing protective clothing will be able to effective on incresing the comfort by allowing heat and vapour transfer between the clothing layers. Because the thermal insulation properties determine the elemantary function of apperals. Therefore, thermal clothing comfort can he estimated with analysing thermal insulation parameters.