PURPOSE: To achieve saving of energy of a paper collecting device attached to a thermal shock testing apparatus and to prevent an operator from being in touch with a sample turned to high or low temperatures immediately after the completion of a thermal shock test.

CONSTITUTION: The cold/hot shock testing apparatus of a liquid tank model is provided with a low temperature tank 2 storing a low temperature liquid and a high temperature tank 3 storing a high-temperature liquid in a chamber 1 with an opening/closing door 13. A thermal shock of a sample can be tested by the apparatus. A paper collecting device consisting of a condenser 14, a water separating means 16 subsequent to the condenser 14 and a testing liquid regenerating means 17 is additionally provided, which is controlled to operate only for a predetermined time after a thermal shock test is completed. Moreover, the opening/closing door 13 of the chamber 1 is controlled not to open during the operating time of the device.