A thermal spray powder of the present invention contains a rare earth element and a group 2 element, which belongs to group 2 of the periodic table. The thermal spray powder, which contains a rare earth element and a group 2 element, is formed, for example, from a mixture of a rare earth element compound and a group 2 element compound or from a compound or solid solution containing a rare earth element and a group 2 element. The thermal spray powder may further contain a diluent element that is not a rare earth element or a group 2 element and is not oxygen, which is at least one element selected, for example, from titanium, zirconium, hafnium, vanadium, niobium, tantalum, zinc, boron, aluminum, gallium, silicon, molybdenum, tungsten, manganese, germanium, and phosphorus.