TWI829881B

A method of producing a melt includes contacting a first heating element directly with an inside of a solid-liquid mixture layer including a batch raw material of glass and a mixture of solid and liquid phases denatured from the batch raw material to apply thermal energy to the solid-liquid mixture layer by heat transfer from the first heating element, supplying the batch raw material from the above of the solid-liquid mixture layer, and continuously producing a liquid phase melt with a bulk density greater than that of the solid-liquid mixture layer in a lower layer in contact with the solid-liquid mixture layer.