Abstract: A pot having an automatic sealing function for heating and cooking food material is disclosed. In the pot having the construction that a lid (20) to which a knob (3) is assembled is installed on the upper part of a vessel (10) whose upper part is opened, it includes an elastic open seal part (40) installed between the lid (20) and the knob (30) so that high pressure generated in heating is automatically exhausted, simultaneously exterior air cannot flow in when the pot is cooled, and thereby the pot interior can be automatically sealed; a sealing part (50) installed between the vessel (10) and the lid (20); and an inverse outflow cut-off flange (60) installed on the lower part of the lid (20), for restraining an outflow of the food material to the exterior of the vessel when contents are boiled.