An injection needle 1 made of an alloy containing cobalt and molybdenum is manufactured as follows. First, lancet cut is carried out to a pipe-like metallic material composed of the alloy containing cobalt and molybdenum to form a blade tip 3 and a blade part 5. Then, a distal end part 1A including the blade tip 3 is mechanically polished, and thereafter, the distal end part 1A is immersed in an electrolytic solution and electrolytically polished. Thus, burrs at the blade tip 3 or the like generated during mechanical polishing are removed. Since the injection needle 1 is composed of the alloy containing cobalt and molybdenum, compared to a conventional injection needle made of stainless steel, an injection needle in which surface roughness of an inner peripheral surface of the injection needle is low and smooth can be provided.