A noncontact article temperature measuring device adapted for evaluating the quality including the food temperature, freezed/thawed state, presence/absence of bubble based on food capacitance measurement data and for evaluating/controlling the operation of a thawing device and used for a freezing/thawing system so as to solve conventional problems. The measuring device is so provided that an article of food can be passed or is provided on both vertical sides of a space or on the same plane of one of the sides. The measuring device comprises at least a pair of electrodes serving as a capacitance sensor and a capacitance measuring section for measuring the capacitance of the food article placed in the space from the signal generated by the paired electrodes. The capacitance is measured by applying a predetermined voltage between the electrodes, and the temperature of the article is determined and the freezed/thawed state is recognized from the measured capacitance. The voltage applied to the plus electrode is preferably a high-frequency voltage the frequency of which ranges from 50 kHz to 1 MHz. A guard electrode for preventing lines of electric force from diffusing surrounds the plus electrode at an insulation distance is preferably provided.