Abstract: An injection molded product is provided on its surface with a fine grain-like pattern resembling a grain pattern of a natural wooden material. The fine grain-like pattern of the injection molded product 1 (a product part 2) is formed from a molten resin 15 comprising a first material 24 and a second material 25 having a different color, mixed in a substantially separate manner, by feeding the molten resin into a cavity 18 for molding the injection molded product in a form of plural divided streams 26 each having a generally constant width so as to allow the second material to solidify as a trace of each divided streams 26.