PROBLEM TO BE SOLVED: To provide a sealing device and a sealing method which form a narrow-width linear sealed part.SOLUTION: The sealing device 1 includes a pair of processing rolls 10, 20 in which two rotors 11, 21 are arranged so that the rotation center lines 11, 22 of the respective rotors are parallel to each other. A plurality of sealing members 13, 23 are provided in one direction CD at a prescribed interval in a protruded fashion on respective outer circumferential surfaces 11a, 21a of the two rotors 11, 21. A material to be processed is compressed by the sealing member 13 (23) of one processing roll 10 (20) and the opposed surfaces of two sealing members 23, 23 (13, 13) adjacent in one direction CD which form the above prescribed interval of the other processing roll 20 (10).
