Abstract: A lid that covers an entire opening surface of a cooking pan for frying is formed with a transparent window portion that permits the see-through of the inside of the pan, and the lid is provided with a mounting mechanism so as to be mountable on the cooking pan without any fabrication for fitting on the cooking pan, and the lid is also provided with a gas ventilating mechanism for providing a gap to ventilate the gas along the curved opening edge of the cooking pan proper and the lid to capture almost completely the oil splash moving straight forward in the lid mounted condition by utilizing the straight forwardness of the oil splash occurring in the cooking pan and the curved forwardness of the gas, and the lid is provided with an opening/closing mechanism for allowing the lid to be mounted on the cooking pan proper by keeping the narrow gap for preventing a fire from occurring by keeping the oxygen short condition in the cooking pan when the lid is mounted thereof between the opening edge of the pan proper