PURPOSE: To supply air for burning to the upper part of a major combustion region at an adequate flow speed without using an air pressure-raising fan specially provided for that purpose, in the title combustion apparatus for a coal-burning boiler or the like.

CONSTITUTION: In a combustion apparatus using slack coal, part of air for burning is supplied to the interior of a furnace through a burner part 3. The combustion apparatus has an air pressure-raising fan 4 whereby air for drying, pulverizing and conveying is supplied to a slack coal-producing apparatus annexed through an air preheater 6, a branch pipe-line 7 whereby the air out of the air preheater 6 is supplied to the upper part 2 of a major combustion region in the furnace, and a flow control damper 5 provided on the branch pipe-line 7.