Abstract: A method and apparatus for upgrading low rank coal, wherein the sealing efficiency between the inside and the outside of a system and between the successive stages of apparatus is improved. Such improvement is provided between a drying apparatus for drying low rank coal into dried coal and a carbonizing apparatus for carbonizing the dried coal into carbonized coal and between the carbonizing apparatus and a cooling/adsorbing apparatus for cooling said carbonized coal and the cooled carbonized coal is caused to absorb therein a tar produced from the carbonization of the dried coal to thereby provide improved coal. In this method and apparatus inflow of an outside atmosphere from the outside into the inside of the system and mixing of gases between said successive stages of apparatus is restrained so that low rank coal is able to be favorably and consecutively upgraded regardless of operating pressures of the respective stages of apparatus.