Abstract: A method of producing ashless coal used in caking coal for coke for iron making includes a slurry preparation step (S1) of mixing a solvent with coal to prepare a slurry; an extraction step (S2) of extracting the slurry obtained in the slurry preparation step (S1) at a temperature in the range of 400° C. to 420° C. for 20 minutes or less, and then cooling the slurry to 370° C. or lower; a separation step (S3) of separating the slurry obtained in the extraction step (S2) into a liquid portion and a non-liquid portion; and an improved-coal-obtaining step (S4) of separating the solvent from the liquid portion separated in the separation step (S3) to obtain ashless coal which is improved coal.