Combustor

A combustor comprising:

• a combustion chamber including a grate embedded therein and a combustion space formed above the grate;
• a fuel supply portion downwardly connected to a central portion of the grate to supply fuel to an upper portion of the grate;
• an air supply part connected to a side portion of the combustion chamber to be slanted on a horizontal plane, and supplying combustion air such that the combustion air rotates in the combustion space;
• a guide member disposed to protrude toward an inside of the combustion space from an inlet through which the combustion air flows into the combustion space, and opened downwardly so as to guide the combustion air such that the combustion air, supplied by the air supply part, rotates downwardly along an inner wall of the combustion chamber in the combustion space;
• and
• protruding guide lines having a screw line shape and extending to be slanted downwardly on at least one of respective surfaces, which face each other, of the guide member and the inner wall of the combustion chamber.