To provide a flame quenching method for a wood pellet type fuel combustion device capable of quickly and safely carrying out emergency quenching of flame when an abnormal situation occurs during combustion.

When an abnormal situation occurs during regular combustion, supply of pellets into a burner body 17 is stopped, an ash disposal motor is driven to mutually rotate a pair of ash disposal gears 24 and 25 for a predetermined time in inward turning directions, and combustion residue containing ash accumulated in a lower part periphery of the burner body 17 is scraped out toward an ash recovery container side in a lower part through a slit part. By this, almost all of the combustion residue in the burner body 17 is quickly removed, and emergency quenching of flame can be quickly and safely carried out.