To provide an oxygen burner type melting furnace, which melts incineration ashes and incineration fly ashes generating when waste is incinerated in an incineration furnace, capable of stably melting the incineration ashes and incineration fly ashes at low fuel consumption.

An oxygen burner type melting furnace 1 comprises a melting furnace body 4 of refractory structure including an incineration fly ash melting chamber 2 having a circular cross section and an incineration ash melting chamber 3 communicating therewith, into which a high-temperature combustion exhaust gas G generated in the incineration fly ash melting chamber 2 flows, and an oxygen burner 5 provided downwardly on the ceiling wall 4b of the incineration fly ash melting chamber 2 in the melting furnace body 4 so as to melt incineration fly ashes D and incineration ashes D' generated by incinerating waste. The incineration fly ashes D are fed into the high temperature flame of the oxygen burner 5 by gaseous transport for combustion melting in the incineration fly ash melting chamber 2, while the incineration ashes D' are fed to the incineration ash melting chamber 3 to contact a high temperature combustion exhaust gas G flowing into the incineration ash melting chamber 3 from the incineration fly ash melting chamber 2 so as to be melted by heating from the surface side thereof in the incineration ahs melting chamber 3.