Provided is a suture instrument capable of shortening operation time required to ligate a wound, and cauterizing the wound. Provided is a surgical needle including a shape memory alloy which has been shape memory-processed to return, at a temperature equal to or higher than its transformation point, to its original shape selected from a group consisting of a ring shape, a spiral shape, a coil shape and a clinch shape. Use of the surgical needle of the present invention makes it unnecessary to employ a threaded suture needle, shortens the operation time required to ligate an incised part or a wound in an organ such as the digestive tract in the body or the skin or the like, and allows cauterization of the wound.
