A method of producing a transdermal absorption sheet includes a preparatory step of forming the sheet portion in advance by drying and solidifying a base solution in a thin film state, a drug solution arrangement step of arranging a drug solution on a surface of a mold having needle-like recessed portions, a drug solution filling step of filling the needle-like recessed portions with the drug solution while pressingly expanding the drug solution on the surface of the mold by pressing the drug solution on the surface of the mold to the surface of the mold with the sheet portion, a drying step of drying an undried drug solution filling the needle-like recessed portions with the sheet portion to form needle-like protruding portions on a lower surface of the sheet portion, and a peeling-off step of peeling off the sheet portion and the needle-like protruding portions from the mold.
