Abstract. Biofoam is a replacement packaging for Styrofoam made from natural fibres that are naturally biodegradable and food-safe. Many studies use chemicals and starch as a matrix adhesive in the manufacture of biofoam. In previous studies, biofoam cups have been developed using the mold Rhizopus oligosporus which is found in coconut fibre. The objective of this study was to analyse the physical, thermal and functional groups’ characteristics in order to determine the most durable biofoam cup. The mixtures of fibre, tempeh mold, and soy flour were fermented for 3 days at 35°C in two stacked plastic cups and were dried for 46 hours at 50°C to stop the fermentation process. The biofoam cups were then analysed for the physical, thermal and functional groups’ characteristics. The most favourable characteristics of the biofoam cup is not easily destroyed and resistant to heat. The results showed that it had 0.08 g/cm3 ± 0.1 g/cm3 of density and 320.54°C of thermal gravimetry analysis. It also had a hydroxyl functional group (O-H) at wave number 3273.20 cm-1 , an alkyl group (C-H) at wave number 2937.59 cm-1 , a carbonyl group (C=O) at wave number 1654.92 cm-1 , 1535.34 cm-1 , and 1259.52 cm-1 , and the C-O functional group at the wave number 1060.85 cm-1 .