A sintered rare earth oxyfluoride compact is composed of LnaObFc (wherein Ln is a rare earth element; and a, b, and c each independently represent a positive number, provided that they are not equal to each other) or Ca-stabilized LnOF as a primary phase and LnOF unstabilized with Ca as a secondary phase. The intensity ratio of the XRD peak of the (018) or (110) plane of the unstabilized LnOF to the highest XRD peak of LnaObFc is preferably 0.5% to 30%.