There is provided a manufacturing method of a tank including a liner. The manufacturing method comprises (A) a process of winding fibers in a sheet-like form impregnated with a resin on a mandrel having a higher rigidity than rigidity of the liner and heating and curing the wound fibers in the sheet-like form to form a sheet layer; (B) a process of pulling out the mandrel from the sheet layer; and (C) fitting the liner into the sheet layer, after the process (B).