To provide a branch pipe fitting pipe member and a branch pipe fitting construction method easily and surely separating the top end of a fireplug from the ground surface by 150 mm or more, even if the fireplug is fitted to an existing pipe buried in a shallow layer with an earth covering set to 600 mm under the ground.

This branch pipe fitting pipe member has a split shape and an approximately T shape capable of watertightly retaining the existing pipe A, and is formed with an opening part capable of fitting the fireplug 9 on the way to the approximately T-shaped leg part, and with an opening part capable of watertightly fitting a perforator A perforating the existing pipe A, in the end of the leg part.