PROBLEM TO BE SOLVED: To provide a fixing device for a metal plate to be processed and a fixing method for the metal plate to be processed facilitating fixation of the metal plate to be processed.SOLUTION: A fixing device 1 for a metal plate 7 to be processed used when a large number of through-holes are formed on the metal plate 7 to be processed includes: a base 8 for placing the metal plate 7 to be processed; and a spacer 9 disposed between the base 8 and the metal plate 7 to be processed. The base 8 is provided with fixing means 11 for fixing, by an electromagnet 10, the metal plate 7 to be processed to the base 8 via the spacer 9. The electromagnet 10 has: a center magnet disposed in the base 8 corresponding to the central part of the metal plate 7 to be processed; and an outside magnet disposed outside of the center magnet. To the electromagnet 10, there is connected a control part 13 for energizing the center magnet and the outside magnet respectively, and when fixing the metal plate 7 to be processed
