To provide a joint having a temporary stop valve which is short in excavation length for connection execution of an extension pipe and excellent in workability by placing a cutting-off member in a joint body having an end part for connecting an existing pipe and an end part for connecting the extension pipe, by cutting off a flow passage to the end part for connecting the extension pipe by the movement of the cutting-off member.

A joint body 11 is provided with a socket 111 for connecting an existing pipe and a socket 112 for connecting an extension pipe on both end parts, and is provided with a body part 113 having the expanded inside diameter in a center part. Heating wires 111a, 112a are embedded in an inner layer of the sockets 111, 112, a stopper 111c on which end face of the existing pipe is abutted is projected on an inner circumferential surface to the distal side of the socket 111, and a seal packing is mounted on a corner part of an opening part on the body side of the socket 112 to form a seat 112c. A spherical body 12 of the outside diameter which is larger than the inside diameter of the socket 112 and smaller than the inside diameter of the barrel part 113 is placed in the barrel part 113, and the spherical body 12 is abutted on the seat 112c by the pressure of the fluid flowing into the barrel part 113 form the existing pipe to cut off the flow passage.