Medical connector

A method of using a medical connector, the method comprising:

• providing the medical connector, which comprises:
• a housing comprising:
• a male connector connection portion comprising a male connector connection port having a cylindrical shape,
• a medical instrument connection portion, and
• a valve body housing portion;
• and
• a valve body configured to open and close the male connector connection port, the valve body comprising:
• a head portion, and
• a barrel portion that connects to the head portion,
• wherein the valve body housing portion connects to the male connector connection port and has an inner circumferential surface having a cylindrical shape with an inner diameter that is larger than a diameter of the male connector connection port,
• wherein the head portion of the valve has a slit that extends along an upper surface and an outer circumferential surface of the head portion, and in a natural state in which no compressive force is applied to the head portion in a radial direction, a first width of the head portion, which is a width in a direction perpendicular to the slit, is greater than a second width of the head portion, which is a width in a direction along the slit, and
• wherein the barrel portion has a cylindrical outer circumferential surface with an outer diameter that is substantially coincident with the inner diameter of the inner circumferential surface of the valve body housing portion;
• and
• inserting a male connector into the male connector connection port such that the head portion moves from the male connector connection port into the valve body housing portion and the slit opens, and a flow passage from the male connector connection portion to the medical instrument connection portion is formed.