PROBLEM TO BE SOLVED: To provide a surgical instrument capable of reducing risks of nerve damages when executing a surgery and improving work efficiency and safety even when performing a surgery of bilateral decompression through a unilateral approach or the like under direct vision or under a microscope.SOLUTION: A surgical instrument 1 includes: a grip part 2 a shaft 3 extended from the grip part 2 a curved head part 4 provided on a distal end of the shaft 3 and a planar mirror surface 5a provided on a part of the head part 4. Also, the mirror surface 5a is provided on a surface 4a on the inner side of the head part 4, and an outer circumferential part 5b of the mirror surface 5a is smoothly continued with a circumferential edge part 4c of the mirror surface 5a in the head part 4.