Provided are: a method for producing coffee beans whereby, in the production of coffee beans roasted to a desired level, coffee beans having an exact roasting level can be produced without depending on the skill of an operator producing the coffee beans a coffee bean roaster and a method for determining the amount of carbon monoxide generated from roasted coffee beans. The method for producing coffee beans, said method involving a step for supplying heat to coffee beans and thus roasting the coffee beans, comprises a step for measuring the amount of carbon monoxide generated from the coffee beans during roasting, and a step for adjusting roasting conditions in the roasting step depending on the results obtained by the measurement of the amount of carbon monoxide.
