The present invention provides a port production method capable of reducing production time. The port production method comprises: inserting a sealing plug which allows a hollow needle to pass therethrough into a tubular part which is to be sealed and which has a first end and a second end on the opposite side from the first end, said part to be sealed being part of a port main body which comprises the part to be sealed, a tubular connection part that continues from the first end of the part to be sealed, and a catching part formed on any of the inner circumferential surface of the part to be sealed, the outer circumferential surface of the part to be sealed, or the second end of the part to be sealed； fitting the catching part and a latching part of a retaining member together, the retaining member comprising both a main part having a first surface and a second surface on the opposite side from the first surface, and the latching part, which continues from the main body； and laying the main body over the sealing plug.
