A seal member is between a combustor around a rotor axis and a vane on a downstream side in an axial direction and defining a part of a combustion gas flow passage through which combustion gas is configured to flow, the seal member being configured to seal a gap between the combustor and the vane. The seal member has: an end face that faces the downstream side in the axial direction so as to face a lateral end face of the vane facing an upstream side in the axial direction; cooling channels through which cooling air is configured to be discharged from a plurality of openings defined in the end face in an array in a circumferential direction based on the rotor axis; and a clearance forming portion that protrudes further toward the downstream side in the axial direction than the end face in which the openings are defined.