To provide a metal seal material without influencing an environment by generation of discharging gas, exhibiting stable sealability, by holding uniform contact bearing pressure, even if partial loading of a mating surface is caused, by absorbing the thermal expansion and a dimensional error even in a rectangular opening part.

The annular plate-like metal seal material is installed in a seal groove, and includes a fulcrum part abutting on a hinge part erected on one side sidewall of the seal groove, a seal area part extended to the opposite side of the seal groove from the fulcrum part and a spring area part extended to the seal groove side from the fulcrum part. The seal area part includes a seal part projected in the direction for abutting on an abutting object member abutting on the metal seal material, and the spring area part includes a spring part having spring elasticity.