To provide a medical instrument for enabling a functional portion provided at the front end of the instrument to be attached and detached to be disposable, while enabling the angle to be adjusted freely to ensure excellent visual recognition, in a medical instrument 10A provided with a rod-shaped grasp portion 20 at its base end and a functional portion 40A used in a medical practice at its front end, a shape memory portion 30 made of a rod-shaped shape memory alloy is provided in between the grasp portion 20 and the functional portion 40A, the grasp portion 20, the functional portion 40A and the shape memory portion 30 are made mutually attachable and detachable, and the shape memory portion 30 is subjected to memory treatment in a linear state, is bent as necessary to use, and is returned to its original shape subjected to the memory treatment by heating the shape memory portion 30 to a memory recovery temperature after using.
