A multi-stack material includes a plurality of fiber-reinforced sheets that are laminated. The fiber-reinforced sheets include a first fiber-reinforced sheet in which a first fiber extends in a first direction and a second fiber-reinforced sheet in which a second fiber extends in a second direction that is different from the first direction. The first fiber-reinforced sheet has formed therein a plurality of first slits where the first fiber is cut such that each cut-up segment of the first fiber will have an equal length. The second fiber-reinforced sheet has formed therein a plurality of second slits where the second fiber is cut such that each cut-up segment of the second fiber will have an equal length. The first slits and the second slits are arranged so as to overlap with each other when viewed from the direction of lamination.