A suture instrument 1 includes a gripping portion 40 that grips a plurality of tissue pieces S1 and S2 by sandwiching them, and a suture needle 48 that punctures and sutures the plurality of tissue pieces S1 and S2, the suture needle 48 is supported so as to be able to move forwards or backwards relative to the gripping portion 40, and a direction of the forward or backward movement of the suture needle 48 is set in a direction that intersects the tissue pieces S1 and S2 gripped by the gripping portion 40.
