A thermal barrier coating member, at least one of which is configured to be mounted on an inner wall surface (61,65) of a cylinder liner accommodating a piston slidably along an axial direction, the inner wall surface (61,65) facing a combustion chamber of an engine, the thermal barrier coating member comprising: a base layer configured to be detachably fitted into a recess formed in the inner wall surface (61,65) of the cylinder liner; and a thermal barrier coating layer formed on an opposite side of the base layer from the inner wall surface (61,65) of the cylinder liner, wherein the thermal barrier coating layer is configured to be disposed above a piston ring which is positioned at an uppermost position in the axial direction of the cylinder liner when the piston reaches top dead center; wherein the base layer includes: a coated portion on which the thermal barrier coating layer is formed; and an exposed portion on which the thermal barrier coating layer is not formed, and wherein at least a part of the exposed portion has a protrusion which protrudes to the opposite side from the inner wall surface (61,65) with respect to the coated portion; wherein the protrusion includes a lower protrusion formed at a lower end portion of the base layer in the axial direction, and wherein the coated portion is disposed above the lower protrusion in the axial direction; wherein the thermal barrier coating layer has one surface formed on the inside surface of the base layer and the other surface disposed on the opposite side from the one surface, and characterized in that the lower protrusion is disposed radially inward of the other surface of the thermal barrier coating layer a base layer configured to be detachably fitted into a recess formed in the inner wall surface (61,65) of the cylinder liner; and a thermal barrier coating layer formed on an opposite side of the base layer from the inner wall surface (61,65) of the cylinder liner, wherein the thermal barrier coating layer is configured to be disposed above a piston ring which is positioned at an uppermost position in the axial direction of the cylinder liner when the piston reaches top dead center; wherein the base layer includes: a coated portion on which the thermal barrier coating layer is formed; and an exposed portion on which the thermal barrier coating layer is not formed, and a coated portion on which the thermal barrier coating layer is formed; and an exposed portion on which the thermal barrier coating layer is not formed, and wherein at least a part of the exposed portion has a protrusion which protrudes to the opposite side from the inner wall surface (61,65) with respect to the coated portion; wherein the protrusion includes a lower protrusion formed at a lower end portion of the base layer in the axial direction, and wherein the coated portion is disposed above the lower protrusion in the axial direction; wherein the thermal barrier coating layer has one surface formed on the inside surface of the base layer and the other surface disposed on the opposite side from the one surface, and characterized in that the lower protrusion is disposed radially inward of the other surface of the thermal barrier coating layer