A method for manufacturing a metal plate, the metal plate including a first surface and a second surface positioned on the opposite side of the first surface, may include a step of rolling a base metal having an iron alloy containing nickel to produce the metal plate. The metal plate may include particles containing as a main component an element other than iron and nickel. In a sample including the first surface and the second surface of the metal plate, the following conditions (1) and (2) regarding the particles may be satisfied:



(1) The number of the particles having an equivalent circle diameter of 1 μm or more is 50 or more and 3000 or less per 1 mm3 in the sample, and
(2) The number of the particles having an equivalent circle diameter of 3 μm or more is 50 or less per 1 mm3 in the sample.