The invention relates to a method for manufacturing a dental scaler tip using a powder injection molding process, a mould, and a scaler tip that is excellent in shape-reliability and injects fluid to a front end thereof along a curved section of the tip. The method comprises the steps of preparing feedstock and injecting the feed stock into a mould to form a molding body, wherein, the mould comprises an operating section to which cylindrical core pins having multi steps and an eccentric end formed at a front end thereof for forming the fluid passage is mounted; and a pair of slide cores disposed for supporting the eccentric ends of the core pins such that the slide cores face each other and are slid in the direction perpendicular to the movement direction of the core pins to form a cavity corresponding to a shape of an article to be formed.