An access port is fixed to a biological membrane, such as a pericardium, in a state in which it penetrates the biological membrane. Provided is an access port including a tubular member having a through-hole passing therethrough in an axial direction, a needle-like member having a tip pointing toward a rear end of the tubular member and mounted to an outer surface of the tubular member, and a manipulating means for switching between a state in which the tip is projected and a state in which it is not projected.