A coffee bean roaster and a method for roasting coffee beans using the roaster are disclosed. The coffee bean roaster includes an oven having a ceramic heating plate with a gate, and a rotary sliding unit to enter the gate so as to slide into the ceramic heating plate, so that the rotary sliding unit roasts coffee beans while rolling the coffee beans and spacing the coffee beans from both the ceramic heating plate and a burner. The method for roasting coffee beans using the coffee bean roaster includes entering the rotary sliding unit containing the coffee beans into the oven through the gate so as to place the rotary sliding unit in the oven at a position spaced apart from both the ceramic heating plate and the burner, roasting the coffee beans by far-infrared radiant heat emitted from the ceramic heating plate, and reburning combustion gases, generated from the roasting of the coffee beans, by the burner.