A transdermal administration device includes an administration section and a support body. An administration section includes a base having a base surface, and a projection protruding from base surface and having a peripheral surface, the projection including a flow path which extends through the projection to the peripheral surface and is open to the peripheral surface. A support body includes a plurality of support sections configured to abut a target of administration. When viewed in a direction facing base surface, the plurality of support sections surround the base surface with a gap between the adjacent support sections and between the base surface and the support sections. The transdermal administration device is configured to displace the projection relative to the support sections from a position in a space surrounded by the plurality of support sections toward outside the space in an extending direction of the projection.
