A package structure, in which a drug-containing pressure-sensitive adhesive sheet comprising a support, a drug-containing pressure-sensitive adhesive layer, and a separator in this order is packaged and sealed in a packaging material, is disclosed, wherein unevenness is provided on at least one of the surface of the support on the side in contact with the inside of the packaging material, the surface of the separator on the side in contact with the inside of the packaging material, and the inside surface of the packaging material. The unevenness reduces the contact area between the packaging material and the sheet so that an adhesive, a plasticizer or any liquid component of the adhesive layer is prevented from adhering to the inside of the packaging material. Therefore, the sheet can easily be taken out of unit package on use.