To provide a seal structure preventing deterioration of seal performance even when at least one of a first member and a second member which oppose to each other and form a space between them is deformed (thermal elongation, etc.) in any of a vertical direction and a parallel direction with respect to surfaces of the first and second members.

The seal structure includes the first and second members which oppose to each other and form the space between them, and seals the space. A plurality of seal fins on the first member side projecting to the surface of the second member and arranged between a high pressure side and a low pressure side are provided on the surface of the first member, and a plurality of seal fins on the second member side projecting to the surface of the first member and arranged between the high pressure side and the low pressure side are provided on the surface of the second member. Both of the seal fins on the first member side and the seal fins on the second member side are formed of an elastic material, and the seal fins on the first member side and the seal fins on the second member side are arranged to overlap with spacing on the first member and the second member, respectively.