Gasket and fuel cell stack including gasket

A gasket configured to be caught between a first fuel cell and a second fuel cell, the gasket being configured to surround a sealed area and to be compressed in a height direction between the first fuel cell and the second fuel cell to seal the sealed area, the gasket comprising:

• a first sealing part configured to surround the sealed area;
• and
• a second sealing part configured to surround the sealed area and the first sealing part, wherein,
• in the first sealing part, a first compressive deformation ratio at a first section configured to be arranged on a side of the gasket facing the first fuel cell is greater than a second compressive deformation ratio at a second section configured to be arranged on a side of the gasket facing the second fuel cell,
• in the second sealing part, a third compressive deformation ratio at a third section configured to be arranged on the side of the gasket facing the second fuel cell is greater than a fourth compressive deformation ratio at a fourth section configured to be arranged on the side of the gasket facing the first fuel cell, and
• each of the first, second, third, and fourth compressive deformation ratios is defined as a ratio of a deformation amount in the height direction of the first, second, third, and fourth sections, respectively, to pressure applied to the first, second, third, and fourth sections, respectively, in the height direction.