<;P>;PROBLEM TO BE SOLVED: To provide a temperature and humidity control device capable of controlling temperature and humidity in a horticultural house etc. while reducing fuel cost. <;P>;SOLUTION: The temperature and humidity control device 1 performing heating in the nighttime and humidification in the daytime includes: an adsorbent 9 capable of adsorbing/desorbing moisture; an air flowing means 5 making air flow along a route 3 coming into contact with the adsorbent 9; a heating means 7 heating in the daytime air on the upstream side from the adsorbent 9 in the route 3; and a high-humidity air supply means supplying in the nighttime air with higher relative humidity than that of the air heated by the heating means 7 to the upstream side in the route 3. <;P>;COPYRIGHT: (C)2011,JPO&INPIT