A forming system for expanding and forming a metal pipe in a die , comprising: a preliminary forming apparatus for preliminary forming a metal pipe material ; a forming apparatus which includes a gas supply unit for supplying gas into a preliminary-formed and heated metal pipe material to expand the metal pipe material and a main body portion to which the die is attached; and a cutting device for cutting at least a portion of the formed metal pipe , wherein the gas supply unit is provided so as not to be disposed on a first straight line (L1) which connects the preliminary forming apparatus and the main body portion in a plan view and a second straight line (L2) which connects the cutting device and the main body portion in a plan view; characterized in that in a case where horizontal directions orthogonal to each other with respect to a center of the forming apparatus are a first direction (X) and a second direction (Y), the preliminary forming apparatus and the cutting device are disposed on one side in the first direction (X) from the forming apparatus , wherein the preliminary forming apparatus is disposed on one side in the second direction (Y) from the forming apparatus , wherein the cutting device is disposed on the other side in the second direction (Y) from the forming apparatus , and wherein the forming system further comprises: a first device for transporting the metal pipe material from the preliminary forming apparatus to the forming apparatus ; and a second, device for transporting the metal pipe from the forming apparatus to the cutting device . a preliminary forming apparatus for preliminary forming a metal pipe material ; a forming apparatus which includes a gas supply unit for supplying gas into a preliminary-formed and heated metal pipe material to expand the metal pipe material and a main body portion to which the die is attached; and a cutting device for cutting at least a portion of the formed metal pipe , wherein the gas supply unit is provided so as not to be disposed on a first straight line (L1) which connects the preliminary forming apparatus and the main body portion in a plan view and a second straight line (L2) which connects the cutting device and the main body portion in a plan view; characterized in that in a case where horizontal directions orthogonal to each other with respect to a center of the forming apparatus are a first direction (X) and a second direction (Y), the preliminary forming apparatus and the cutting device are disposed on one side in the first direction (X) from the forming apparatus , wherein the preliminary forming apparatus is disposed on one side in the second direction (Y) from the forming apparatus , wherein the cutting device is disposed on the other side in the second direction (Y) from the forming apparatus , and wherein the forming system further comprises: a first device for transporting the metal pipe material from the preliminary forming apparatus to the forming apparatus ; and a second, device for transporting the metal pipe from the forming apparatus to the cutting device . a first device for transporting the metal pipe material from the preliminary forming apparatus to the forming apparatus ; and a second, device for transporting the metal pipe from the forming apparatus to the cutting device . <EOS>