A drug administration device includes a substrate having a first surface, a projection extending from the first surface, and a solid drug. One direction that intersects with the first surface is a first direction, and one direction that extends along the first surface is a second direction. A groove serving as a receiving section is formed in the projection. The groove defines a cavity recessed in the first direction toward the substrate and extends in the second direction to open to a section of the peripheral surface of the projection. The drug is received in the groove.