To easily and reliably enhance a sealing effect without using a sealing plug by only installing packing or an O-ring in a cylindrical part of a hole saw, or installing or fixing the packing or the O-ring on the joint side.

In a service tee joint by installing rubber packing 14 on a cylindrical part 12 of a hole saw 7 composed of the cylindrical part 12 having an edge and a main body 13 having a diameter larger than the cylindrical part 12 and having a male screw on the outer periphery, the hole saw 7 is screwed in until the rubber packing 14 is press-fitted to a main pipe 6 by using a tool when requiring to seal an opening part 15 after boring a hole in the main pipe 6. In the hole saw 7 having a through-hole, the through-hole is sealed by a section 11 when hollowing out the main pipe 6, but a seal is maintained even if the through-hole of the hole saw 7 is formed in a blind hole shape by a fixation of a block piece or even if the section 11 does not exist.