the cooling cycle the heater 10 is de energized to stop heating of the adsorbent 9 after the cooling chamber 6 is emptied an article to be cooled is placed in the cooling chamber 6 and then the cover 2 is set on the cooler body 1 to close the cooling chamber 6 thereafter the cooler is allowed to stand for a while during that time since the outer wall 4 is still hot air existing around the outer wall 4 is heated and reduced in density consequently the air moves upward toward the air outlet 15 and thence is liberated from the air outlets 15 at the same time fresh air flows from the air inlet 14 into the air flow passage 8 thus the convection is created within the air flow passage 8 in this instance the outer wall 4 constitutes a heat radiating portion so that the adsorbent 9 is gradually cooled in order to improve the cooling efficiency it is possible to provide heat radiating fins on the outside surface of the outer wall 4 due to a temperature drop of the adsorbent 9 the equilibrium of adsorption changes whereupon absorption of the working medium on the adsorbent 9 begins the working medium i e ethanol in the illustrated embodiment retained on the working medium retaining member 13 in the liquid phase evaporates and moves radially outwardly across the reaction chamber 7 in the vapor phase and then is adsorbed on the adsorbent 9 the heat produced by adsorption of the.