An injection molding machine which monitors a state of resin in an injection cylinder (20) includes an energy consumption detecting part (10) which detects an amount of energy consumed in plasticizing resin. The injection molding machine also includes a molding quality judging part (11) which judges molding quality based on the consumed energy detected by the energy consumption detecting part (10) and an energy consumption stabilizing part (12) which stabilizes the consumed energy detected by the energy consumption detecting part.