There is provided a method for plasma heat treatment that can suppress the degradation of thermal efficiency even in the case where plasma is used to heat a sample at a temperature of 1,200\xb0 C. In one embodiment, each of the jump wings 11, 11 comprises divided wing components laterally spaced in a direction S perpendicular to a sheet transfer direction T. For a current activity value associated with the functional unit in the set of functional units, a determination is made as to whether a thermal level associated with the functional unit differs from a verified thermal level beyond a predetermined threshold.