PURPOSE: To make convinient and facilitate a mounting work of a piping terminal appliance to a flexible pipe and to simplify the maintenance after the construction.

CONSTITUTION: A piping member installation jig 9 used in the case a piping member consisting of a water supply pipe 5 and an elbow joint 6 is fixed to a jig installation member 3b is equipped with a casing 10 capable of being fixed to the jig installation member 3b, an introduction holding hole 11 capable of introducing and withdrawing a pipe bearing metal fixture 7 is formed in the casing 10, and a pipe connection 7d is formed in the pipe bearing metal fixture 7. An interlocking mechanism 13 capable of fixing and releasing the pipe bearing metal fixture 7 introduced into the introduction holding hole 11 against the casing 10 is provided thereto, and an operating section 16a capable of controlling the interlocking mechanism 13 from the outside is provided.