Provided are a processing apparatus (1) and a method capable of accurately measuring a real temperature of a workpiece contained and heated in a chamber. The processing apparatus (1) comprises a chamber (2) containing a workpiece (W), a measurement piece (6) installed in the chamber (2), and a measuring unit (8). The measurement piece (6) is capable of thermal expansion and contraction in response to an internal temperature of the chamber (2). The measuring unit (8) measures a thermal expansion and contraction amount of the measurement piece (6) to thereby measure the real temperature of the workpiece (W).
