A hermetic seal cover capable of inhibiting defects such as voids from generating in sealing a package, and a method of manufacturing the seal cover are provided. The hermetic seal cover comprises: a seal cover main body; a Ni plating layer applied onto a surface of the seal cover main body; and a Au--Sn brazing material layer fusion bonded to a surface of the Ni plating layer, and is characterized by a Ni--Sn ally layer disposed between the Ni plating layer and the Au--Sn brazing material layer. It is preferable if the Ni--Sn alloy layer has a thickness of 0.6-5.0 .mu.m. It is also preferable if Au--Sn brazing material layer has a Sn content of 20.65-23.5 wt %.