Patent ID: 8333176

Claim:
A connector to be connected to a connection member in which a fluid flows, and to be sealed by using an O-ring between the connector and a cylindrical outer peripheral surface of the connection member, the connector comprising: a body portion having an inner peripheral surface defining a cylindrical insertion hole for inserting therein the connection member and the O-ring, the cylindrical insertion hole being provided with an arrangement position of the O-ring; and a recess portion provided in the inner peripheral surface of the body portion and opened in the body portion in a radial direction of the body portion, at a position on an inlet side of the insertion hole relative the arrangement position of the O-ring, wherein the recess portion extends in an axial direction of the body portion and has an end portion on a side of the arrangement position of the O-ring, and the end portion of the recess portion becomes in an acute angle shape which is acute toward the arrangement position of the O-ring.