A method for producing an ashless coal includes a slurry preparation, an extraction, a separation, an ashless coal acquirement, and a by-product acquirement. In the by-product acquirement, a solvent used in the slurry preparation is evaporated and separated from a solid-content concentrated liquid separated in the separation, and then, a by-product coal is acquired. The by-product coal is used as a fuel for heating a slurry obtained in the slurry preparation.