PURPOSE: To provide a branching method for a pipe line to a customer capable PVi of reducing a construction interval and a construction period of a pipe line branching and preventing traffic obstacle due to this construction.

CONSTITUTION: When a branching hole 11 of a pipe body 7 is closed by a lid member 17 and arranged to a line 28 and placed in a ground and branching is provided to this pipe line 28, the lid member 17 is removed from the pipe body 7 along a digging hole from surface ground side mounted to a placed branching hole 11 of the pipe body 7. A branching short pipe 20 pulled down along the digging hole is connected with the branching hole 11 of the pipe body 7 instead of this lid member 17 and the lid member 17 is replaced by the branching short pipe 20 and the pipe line 28 is branched.