Provided is an injection molding composition which is high in thermal decomposability and is not easily deformed by debinding when the composition is heated and which can further give a satisfactory debound body in a short period even when the debound body originates from a molded body having a large wall thickness. The composition is an injection molding composition comprising a metallic powder that can be sintered, and an organic binder, in which the organic binder is constituted of a polylactic acid (a), a polyoxymethylene (b), a polypropylene (c), an organic compound (d) having a viscosity of 200 mPa·s or less at 150°C, and a thermoplastic resin (e) having a Vicat softening temperature of 130°C or lower.