Manufacturing method of tank

A manufacturing method of a tank in which a carbon fiber layer is impregnated with a resin, the manufacturing method comprising:

• first disposing, of disposing a semi-finished product of the tank before being impregnated with the resin in a cavity of a mold, in which the mold includes a runner connected to the cavity, an extrusion hole branching from the runner, and an extruder slidably disposed inside the extrusion hole;
• first injecting, of injecting the resin into the cavity through the runner, following the first disposing;
• second disposing, of disposing a colorant in the extrusion hole following the first injecting;
• and
• second injecting, of injecting the resin into the cavity of the mold through the runner while pushing the extruder toward the runner, following the second disposing.