Coffee roaster

An automatic coffee roaster having a compact structure, comprising a rotatable drum provided at a side thereof with a plurality of ventilation holes, an air supplying duct arranged at a lower portion of said roaster below said drum and provided therein with a heater, for heating the air to roast coffee beans, and a fan, which heater and fan are separated from each other by an air flow rate adjusting plate, an exhaust duct arranged at an upper portion of the roaster above said drum and provided therein with a hood for covering an inlet portion of the duct, a recovery vessel for receiving thin husks which become separated from the coffee beans, a roasting control mechanism including a switching device which disconnects said heater on receipt of a detection signal from a temperature sensing device which is mounted on an inner surface of said drum so as to detect the surface temperature of coffee beans therein, and an air supply control mechanism, including an air flow adjustor device, connected to said switching device which operates to open the adjusting plate so as to increase air flow to the drum for rapidly cooling the roasted coffee beans at the same time as said heater is disconnected, the air flow adjustor device normally operating to close said adjusting plate so as to supply a small volume of air flow to said drum through the small perforation holes located in the adjusting plate, which air is heated during the roasting operation, whereby coffee beans are homogeneously roasted and thereafter rapidly cooled in said roaster through automatic consecutive operations while effecting efficient recovery of the thin husks which become separated from the coffee beans during roasting.