A manufacturing method of a multi-laminated body comprising: a step 1 (L-flow path) for vertically dividing a laminated flow obtained by arranging at least two molten resins adjacent to each other in a lengthwise direction into two sections, and forming an upper laminated flow and a lower laminated flow obtained by the division into a first laminated flow and a second laminated flow respectively, guiding the first laminated flow to a left direction relative to a flow direction, guiding the second laminated flow to a right direction relative to the flow direction, then guiding the first laminated flow to a lower right direction toward a center of the flow direction, guiding the second laminated flow to an upper left direction toward the center of the flow direction, and then rearranging the first and second laminated flows adjacent to each other in a horizontal direction and thereby joining the first and second laminated flows together; and a step 2 (R-flow path) for vertically dividing a laminated flow obtained by arranging at least two molten resins adjacent to each other in a lengthwise direction into two sections, and forming an upper laminated flow and a lower laminated flow obtained by the division into a third laminated flow and a fourth laminated flow respectively, guiding the third laminated flow to a right direction relative to a flow direction, guiding the fourth laminated flow to a left direction relative to the flow direction, then guiding the third laminated flow to a lower left direction toward a center of the flow direction, guiding the fourth laminated flow to an upper right direction toward the center of the flow direction, and then rearranging the third and fourth laminated flows adjacent to each other in a horizontal direction and thereby joining the third and fourth laminated flows together, wherein the step 1 (L-flow path) and the step 2 (R-flow path) are alternately repeated in this listed order, and a number of the steps to be performed is at least three. a step 1 (L-flow path) for vertically dividing a laminated flow obtained by arranging at least two molten resins adjacent to each other in a lengthwise direction into two sections, and forming an upper laminated flow and a lower laminated flow obtained by the division into a first laminated flow and a second laminated flow respectively, guiding the first laminated flow to a left direction relative to a flow direction, guiding the second laminated flow to a right direction relative to the flow direction, then guiding the first laminated flow to a lower right direction toward a center of the flow direction, guiding the second laminated flow to an upper left direction toward the center of the flow direction, and then rearranging the first and second laminated flows adjacent to each other in a horizontal direction and thereby joining the first and second laminated flows together; and a step 2 (R-flow path) for vertically dividing a laminated flow obtained by arranging at least two molten resins adjacent to each other in a lengthwise direction into two sections, and forming an upper laminated flow and a lower laminated flow obtained by the division into a third laminated flow and a fourth laminated flow respectively, guiding the third laminated flow to a right direction relative to a flow direction, guiding the fourth laminated flow to a left direction relative to the flow direction, then guiding the third laminated flow to a lower left direction toward a center of the flow direction, guiding the fourth laminated flow to an upper right direction toward the center of the flow direction, and then rearranging the third and fourth laminated flows adjacent to each other in a horizontal direction and thereby joining the third and fourth laminated flows together,