A pipe making machine (1) is provided with a frame (2) which is mounted inside an existing pipe (200), a joining mechanism (4) which joins portions of a synthetic resin, belt-like body (100), and a wheel (6) which supports the joining mechanism (4) on the inner surface of the existing pipe (200). The joining mechanism (4) is provided with an inner roller (42) and an outer roller (43) which clamp the synthetic resin, belt-like body (100) from the inside and outside thereof. The rotation shaft of the wheel (6) is located at a position different from the positions of the rotation shafts of the inner roller (42) and the outer roller (43). The outer roller (43) of the joining mechanism (4) is maintained so as to be spaced away from the inner surface of the existing pipe (200).