A combustor liner used for a gas turbine combustor and forming a combustion chamber, the combustor liner comprising: an outer side wall made of metal; a panel attached to an inner side of the outer side wall and made of a ceramic matrix composite material, the panel including a panel body facing the combustion chamber, a first connection piece rising from an exterior surface of the panel body at a side portion of the panel body and protruding in a lateral direction, and a second connection piece rising from the exterior surface of the panel body at another side portion of the panel body and protruding in the lateral direction; a first connection unit configured to connect the panel to the outer side wall, the first connection unit including a first elastic member configured to bias at least one of the outer side wall and the first connection piece, and a first fixation member made of metal and configured to fix at least one of the first connection piece and the first elastic member to the outer side wall, and a second connection unit configured to connect the panel to the outer side wall, the second connection unit including a second elastic member configured to bias at least one of the outer side wall and the second connection piece, and a second fixation member made of metal and configured to fix at least one of the second connection piece and the second elastic member to the outer side wall, wherein the first connection piece is pressed against the outer side wall by the first elastic member from a combustion chamber side, or the outer side wall is pressed against the first connection piece by the first elastic member from outside of the outer side wall, the second connection piece is pressed against the outer side wall by the second elastic member from the combustion chamber side, or the outer side wall is pressed against the second connection piece by the second elastic member from outside of the outer side wall, a plurality of panels are arranged such that an end surface of the first connection piece of a first panel of the plurality of panels is opposed to an end surface of the second connection piece of an adjacent second panel of the plurality of panels, thereby forming an inner side wall attached to the inner side of the outer side wall, and in each panel of the plurality of panels, the first connection piece is connected to the outer side wall in a state in which the first fixation member of the first connection unit penetrates the first connection piece and the outer side wall, and the second connection piece is connected to the outer side wall in a state in which the second fixation member of the second connection unit penetrates the second connection piece and the outer side wall. an outer side wall made of metal; a panel attached to an inner side of the outer side wall and made of a ceramic matrix composite material, the panel including a panel body facing the combustion chamber, a first connection piece rising from an exterior surface of the panel body at a side portion of the panel body and protruding in a lateral direction, and a second connection piece rising from the exterior surface of the panel body at another side portion of the panel body and protruding in the lateral direction; a first connection unit configured to connect the panel to the outer side wall, the first connection unit including a first elastic member configured to bias at least one of the outer side wall and the first connection piece, and a first fixation member made of metal and configured to fix at least one of the first connection piece and the first elastic member to the outer side wall, and a second connection unit configured to connect the panel to the outer side wall, the second connection unit including a second elastic member configured to bias at least one of the outer side wall and the second connection piece, and a second fixation member made of metal and configured to fix at least one of the second connection piece and the second elastic member to the outer side wall, wherein the first connection piece is pressed against the outer side wall by the first elastic member from a combustion chamber side, or the outer side wall is pressed against the first connection piece by the first elastic member from outside of the outer side wall, the second connection piece is pressed against the outer side wall by the second elastic member from the combustion chamber side, or the outer side wall is pressed against the second connection piece by the second elastic member from outside of the outer side wall, a plurality of panels are arranged such that an end surface of the first connection piece of a first panel of the plurality of panels is opposed to an end surface of the second connection piece of an adjacent second panel of the plurality of panels, thereby forming an inner side wall attached to the inner side of the outer side wall, and in each panel of the plurality of panels, the first connection piece is connected to the outer side wall in a state in which the first fixation member of the first connection unit penetrates the first connection piece and the outer side wall, and the second connection piece is connected to the outer side wall in a state in which the second fixation member of the second connection unit penetrates the second connection piece and the outer side wall.