A 0.96 mass% C steel coated with chromium carbides was brazed to Si₃N₄ by using Ag-Cu/Ti alloy. Chromium carbides were coated on the steel at 1373K for 2.5 to 36h in an (Ar+HCl) mixture gas using the Cr powder pack process. The obtained coating layer consisted of M₇C₃ and M₂₃C₆ (M=Fe, Cr). The bonding treatment was performed at 1173K for 1h in vacuum. The shear strength of the joint increased with increasing coating layer thickness up to 20μm. The average and maximum shear strengths of the joint with a coating layer of 20μm in thickness were 209 and 258MPa, respectively. Those of the joint without the coating layer were 149 and 218MPa, respectively. The Weibull slopes for the shear strength were 9.4 in the former and 3.8 in the latter. It was considered that the coating layer played an important role as an active layer of interfacial reaction and as a relaxation layer of thermal stress in the joint. The difference in interfacial structures between these joints was also discussed on the basis of TEM observation.