A method for treating roasted coffee beans, to improve an extraction rate of coffee component from the roasted coffee beans and to increase a richness component content of the roasted coffee beans while suppressing acidity generation in the roasted coffee beans, includes: a sugar-enriching treatment step in which roasted coffee beans are brought into contact with sugar to increase a sugar content of the roasted coffee beans and a water vapor treatment step in which the roasted coffee beans having undergone the sugar-enriching treatment are brought into contact with water vapor.
