A burner for an entrained bed gasifier is provided in which a stable ignition is accelerated in the vicinity of a fuel jetting port and a good combustion state is maintained. A fuel (1, 3), such as coal and char etc., and a portion of a gasifying agent (2, 4, 5) are premixed in a burner before they a charged into a gasifier. The burner includes a triple tubular member including an outer tubular portion, an intermediate tubular portion, and an inner tubular portion. A seal gas tube is positioned within the inner tubular portion. At the time when the fuel, such as coal and char etc., and a premixing gas (a portion of the gasifying agent) are charged into the burner, at least any one of the fuel, such as coal and char etc., and the premixing gas is charged in a tangential direction relative to the burner central axis so as to be given a swirling directional velocity component.