Four point bending tests of the brazed joint composed of sintered silicon nitride and 0.2% carbon steel with Cusil ABA filler which were fabricated at 86$0^{circ}C$ were performed at temperatures, 25, 100, 200, 300, 400, 50$0^{circ}C$ From the experiments, the maximum bending strength was measured at 30$0^{circ}C$ From the 3D FE analysis of the residual stress of the brazed joint, it was revealed that the thermally induced residual stresses were minimized when the environmental temperature was 35$0^{circ}C$ Considering the degradation of the filler material at high temperatures, it was calculated that the maximum bending strength of the brazed joint occured just below the temperature of the minimum thermal residual stress and the thermal residual stress was the dominative parameter of the brazed joint.