A multilayer nanofiber sheet (10) includes: a nanofiber layer (11) including nanofibers which comprise a water-soluble polymer compound； a substrate layer (12) arranged on one surface side of the nanofiber layer (11)； and a water-insoluble porous layer (13) arranged on the other surface side of the nanofiber layer (11). The three layers are layered, and the multilayer nanofiber sheet is used in a state in which a surface thereof on the porous layer side is arranged so as to face a surface of an object. Preferably, the three layers are layered in a fixed state. Preferably, the porous layer (13) has a thickness of from 3 to 1000 μm.
