Abstract: Continuous-processing type sterilizer and cooker for providing packaged foods completely sterilized with a small heat-energy consumption and retaining the color, fragrance, taste, texture and quality similar to unprepared foods by taking the steps of immersing a product cage, wherein contains the packaged foods, in pressurized hot-water in a sterilization tank, moving the cage within the hot water by means of a drive means for a given period of time, transferring it through a transfer tank from the hot water to a pressurized cooling water in a cooling tank, and moving it within the cooling water by means of a drive means for a given period of time. Both the sterilization tank and the cooling tank are connected to the transfer tank at their one end, the sterilization tank having a preparatory chamber at its other end and the cooling tank having an off-loading chamber at its other end.