A method for feeding a composite molten resin using an apparatus for feeding a composite molten resin, the apparatus for feeding the composite molten resin having a nozzle portion which includes: - an outer discharge port in which an outermost annular flow path through which a main layer-forming molten resin flows, meets an outer annular flow path through which a sub-layer-forming molten resin flows inside of said outermost annular flow path; and - an inner discharge port in which an inner annular flow path through which a shell layer-forming molten resin flows inside of said outer annular flow path and meets an innermost annular flow path through which a core layer-forming molten resin flows further inside of said inner annular flow path; - said outer discharge port and said inner discharge port being arranged in this order from the downstream toward the upstream in a direction in which the molten resins flow; - wherein provision is made of feeding means for continuously flowing said main layer, characterized in that the used apparatus further comprises: - an opening/closing means for opening and closing said inner discharge port, wherein said opening/closing means is disposed on the axis of said annular flow paths so as to move back and forth in the axial direction, and works as a valve body forming a valve at the distal end thereof to close said inner discharge port, and - an intermittent discharging means for intermittently discharging said sub-layer-forming molten resin; and - a shell body is formed by said opening/closing means by using said core layer-forming molten resin and said shell layer-forming molten resin in a manner that said core layer-forming molten resin is wrapped in said shell layer-forming molten resin, and - after said shell body has passed through said outer discharge port, said sub-layer-forming molten resin presses and deforms the shell body. - an outer discharge port in which an outermost annular flow path through which a main layer-forming molten resin flows, meets an outer annular flow path through which a sub-layer-forming molten resin flows inside of said outermost annular flow path; and - an inner discharge port in which an inner annular flow path through which a shell layer-forming molten resin flows inside of said outer annular flow path and meets an innermost annular flow path through which a core layer-forming molten resin flows further inside of said inner annular flow path; - said outer discharge port and said inner discharge port being arranged in this order from the downstream toward the upstream in a direction in which the molten resins flow; - wherein provision is made of feeding means for continuously flowing said main layer, - an opening/closing means for opening and closing said inner discharge port, wherein said opening/closing means is disposed on the axis of said annular flow paths so as to move back and forth in the axial direction, and works as a valve body forming a valve at the distal end thereof to close said inner discharge port, and - an intermittent discharging means for intermittently discharging said sub-layer-forming molten resin; and - a shell body is formed by said opening/closing means by using said core layer-forming molten resin and said shell layer-forming molten resin in a manner that said core layer-forming molten resin is wrapped in said shell layer-forming molten resin, and - after said shell body has passed through said outer discharge port, said sub-layer-forming molten resin presses and deforms the shell body.