A pipe-forming apparatus (3;3B;3C;3D;3E;3F;3G;3H;3I; 3J;3K;3L;3M;3N;3X;3P;3Q;3R) configured to form a spiral pipe by fitting edges of a strip member adjacent with a difference of one lap with each other while spirally winding the strip member, wherein the pipe-forming apparatus (3;3B;3C;3D;3E;3F;3G;3H;3I;3J;3K;3L;3M;3N;3X;3P;3Q;3R) comprises: an apparatus frame configured to be disposed on a partial part in a circumferential direction of a pipe end portion of a preceding spiral pipe portion configured to be formed in advance of the strip member, the pipe end portion configured to be provided on a forefront side in an extending direction along a pipe axis of the preceding spiral pipe portion, the apparatus frame having a propelling longitudinal direction being along a winding direction of the preceding spiral pipe portion; a driving part provided in the apparatus frame and configured to press an unformed following strip portion of the strip member following the preceding spiral pipe portion obliquely with respect to a machine-height direction of the apparatus frame toward the partial part or a vicinity thereof in the preceding spiral pipe portion, the machine-height direction being along an inward-outward direction of the preceding spiral pipe portion; and a pipe end guide (20;60,70;80) provided in a reverse portion of the apparatus frame in the machine-height direction, the pipe end guide (20;60,70;80) configured to be constrained with respect to the pipe end portion in a machine-width direction orthogonal to the propelling longitudinal direction and the machine-height direction, and the pipe end guide (20;60,70;80) configured to be engaged so as to be slidable with respect to the pipe end portion in the propelling longitudinal direction, characterized in that the pipe end guide (20;60,70;80) includes a flat-shaped receiving portion (21a,22a;63a,73a;81a) along the propelling longitudinal direction and the receiving portion (21a,22a;63a,73a;81a) configures to receive the pipe end portion from the reverse side and apply a reaction force (F 21, F 22) to the pipe end portion against the pressing force (F 10), wherein a radial component force (F 11) of the pressing force (F 10) and the reaction force (F 21, F 22) becomes a fitting force for the fitting and a circumferential component force (F 12) of the pressing force (F 10) becomes a propelling force for forward propulsion, and wherein the pipe-forming apparatus (3;3B;3C;3D;3E;3F;3G;3H; 3I;3J;3K;3L;3M;3N;3X;3P;3Q;3R) is a pipe end release-type pipe-forming apparatus having a non-inner periphery restriction structure. an apparatus frame configured to be disposed on a partial part in a circumferential direction of a pipe end portion of a preceding spiral pipe portion configured to be formed in advance of the strip member, the pipe end portion configured to be provided on a forefront side in an extending direction along a pipe axis of the preceding spiral pipe portion, the apparatus frame having a propelling longitudinal direction being along a winding direction of the preceding spiral pipe portion; a driving part provided in the apparatus frame and configured to press an unformed following strip portion of the strip member following the preceding spiral pipe portion obliquely with respect to a machine-height direction of the apparatus frame toward the partial part or a vicinity thereof in the preceding spiral pipe portion, the machine-height direction being along an inward-outward direction of the preceding spiral pipe portion; and a pipe end guide (20;60,70;80) provided in a reverse portion of the apparatus frame in the machine-height direction, the pipe end guide (20;60,70;80) configured to be constrained with respect to the pipe end portion in a machine-width direction orthogonal to the propelling longitudinal direction and the machine-height direction, and the pipe end guide (20;60,70;80) configured to be engaged so as to be slidable with respect to the pipe end portion in the propelling longitudinal direction, characterized in that the pipe end guide (20;60,70;80) includes a flat-shaped receiving portion (21a,22a;63a,73a;81a) along the propelling longitudinal direction and the receiving portion (21a,22a;63a,73a;81a) configures to receive the pipe end portion from the reverse side and apply a reaction force (F 21, F 22) to the pipe end portion against the pressing force (F 10), wherein a radial component force (F 11) of the pressing force (F 10) and the reaction force (F 21, F 22) becomes a fitting force for the fitting and a circumferential component force (F 12) of the pressing force (F 10) becomes a propelling force for forward propulsion, and wherein the pipe-forming apparatus (3;3B;3C;3D;3E;3F;3G;3H; 3I;3J;3K;3L;3M;3N;3X;3P;3Q;3R) is a pipe end release-type pipe-forming apparatus having a non-inner periphery restriction structure.