To finish part change in a short time by improving workability of part change.

This device has a twisting member twisting thread ends by injecting liquid-added compressed air; a base member 24 provided with the twisting member; a thread piecing unit 22 installed to the base member 24, forming a twisting chamber 23 accommodating the twisting member inside, and having first and second thread guide members 25 and 26 guiding the threads to the twisting member; and a thread piecing device body 21 detachably provided with the tread piecing unit 22, and setting thread ends to the twisting member 31.