A fiber sheet of the present disclosure includes: a first fiber layer including a plurality of first fibers, the plurality of first fibers comprising a thermoplastic polymer and arranged side by side in a first direction; a second fiber layer including a plurality of second fibers, the plurality of second fibers comprising a thermoplastic polymer and arranged side by side in a second direction intersecting the first direction, and disposed to face the first fiber layer; and a nanofiber layer including nanofibers, the nanofibers comprising any one of a thermoplastic polymer, a thermosetting polymer, a biodegradable polymer, and a biological polymer, the nanofiber layer disposed to be in contact with the first fiber layer and the second fiber layer, in which the nanofiber layer is heat-welded to the first fiber layer and the second fiber layer.