A metal nanolaminate includes a plurality of units stacked in a longitudinal direction of the metal nanolaminate. Each of the units includes a first layer and a second layer stacked in the longitudinal direction. The first layer includes a first metal material formed of a first metallic element and the second layer includes the first metal material and a second metal material formed of a second metallic element. Each of the first layer and the second layer has a thickness of at least 5 nm but less than 100 nm in the longitudinal direction.