Abstract: In a method of producing a honeycomb structured body, a die for extrusion molding is provided to produce at least one honeycomb molded body. The die includes a die body having a raw material inlet side face and a molded body extrusion side face. The raw material inlet side face includes raw material supply holes for supplying a ceramic raw material. The molded body extrusion side face includes molding grooves for molding the ceramic raw material into a shape of the at least one honeycomb molded body. The raw material supply holes and the molding grooves communicate with one another through connecting parts provided between the raw material supply holes and the molding grooves. The connecting parts each include, in a cross section substantially parallel to an extruding direction of the ceramic raw material, a curved part and a straight part.