A suturing system comprising: a first endoscope configured to observe a hollow organ and having a pair of channels along a longitudinal direction of the first endoscope; a forceps inserted in one of the pair of channels and configured to grip an edge of a perforation formed on the hollow organ; and a suturing mechanism configured to suture tissues by using a suturing unit having an anchor (106, 107) mounted to an end portion of a suturing thread, the suturing mechanism including a hollow needle tube inserted in the other of the pair of channels, having an inner cavity capable of receiving the anchor (106, 107) to engage with a surrounding tissue of the perforation formed on the hollow organ, and capable of penetrating the surrounding tissue in a state where the forceps grips an edge of the perforation, and a pusher which is inserted through the hollow needle tube in a freely advancing and retracting manner and is capable of pushing the anchor (106, 107) received in the hollow needle tube toward a distal end of the hollow needle tube, characterized in that the suturing system further comprises: a second endoscope, mounted to the distal end portion of the first endoscope, disposed so that the hollow needle tube, the forceps and the second endoscope are arranged in series along a radial direction of the first endoscope, being configured to be inserted into the perforation formed on the hollow organ, and configured to observe a state where the hollow needle tube penetrates the surrounding tissue and protrudes therefrom, from the outside of the hollow organ, wherein the second endoscope is capable of protruding to a more distal side than a distal end of the forceps and the distal end of the hollow needle tube and is capable of bending, and the second endoscope is configured to observe the distal end of the hollow needle tube by protruding and bending toward the distal end of the hollow needle tube. a first endoscope configured to observe a hollow organ and having a pair of channels along a longitudinal direction of the first endoscope; a forceps inserted in one of the pair of channels and configured to grip an edge of a perforation formed on the hollow organ; and a suturing mechanism configured to suture tissues by using a suturing unit having an anchor (106, 107) mounted to an end portion of a suturing thread, the suturing mechanism including a hollow needle tube inserted in the other of the pair of channels, having an inner cavity capable of receiving the anchor (106, 107) to engage with a surrounding tissue of the perforation formed on the hollow organ, and capable of penetrating the surrounding tissue in a state where the forceps grips an edge of the perforation, and a pusher which is inserted through the hollow needle tube in a freely advancing and retracting manner and is capable of pushing the anchor (106, 107) received in the hollow needle tube toward a distal end of the hollow needle tube, a hollow needle tube inserted in the other of the pair of channels, having an inner cavity capable of receiving the anchor (106, 107) to engage with a surrounding tissue of the perforation formed on the hollow organ, and capable of penetrating the surrounding tissue in a state where the forceps grips an edge of the perforation, and a pusher which is inserted through the hollow needle tube in a freely advancing and retracting manner and is capable of pushing the anchor (106, 107) received in the hollow needle tube toward a distal end of the hollow needle tube, characterized in that the suturing system further comprises: a second endoscope, mounted to the distal end portion of the first endoscope, disposed so that the hollow needle tube, the forceps and the second endoscope are arranged in series along a radial direction of the first endoscope, being configured to be inserted into the perforation formed on the hollow organ, and configured to observe a state where the hollow needle tube penetrates the surrounding tissue and protrudes therefrom, from the outside of the hollow organ, wherein the second endoscope is capable of protruding to a more distal side than a distal end of the forceps and the distal end of the hollow needle tube and is capable of bending, and the second endoscope is configured to observe the distal end of the hollow needle tube by protruding and bending toward the distal end of the hollow needle tube. a second endoscope, mounted to the distal end portion of the first endoscope, disposed so that the hollow needle tube, the forceps and the second endoscope are arranged in series along a radial direction of the first endoscope, being configured to be inserted into the perforation formed on the hollow organ, and configured to observe a state where the hollow needle tube penetrates the surrounding tissue and protrudes therefrom, from the outside of the hollow organ, wherein the second endoscope is capable of protruding to a more distal side than a distal end of the forceps and the distal end of the hollow needle tube and is capable of bending, and the second endoscope is configured to observe the distal end of the hollow needle tube by protruding and bending toward the distal end of the hollow needle tube.