Contributing to the confinement safety evaluation of glove boxes (GBs) connected to high-efficiency particle air filters for radioactive materials under fire accidents, combustion tests of a flammable polymer, i.e., polymethyl methacrylate (PMMA), and a flame retardant polymer, i.e., polycarbonate (PC), as typical GB panel resins have been conducted with an engineering-scale combustion apparatus. Combustion properties such as the mass loss rate (MLR) and the heat release rate (HRR) of PMMA and PC were investigated in the combustion tests. From our results, the relationships of MLR and HRR to the surface area of the plate type of PMMA and PC were deduced.