A skin adhesive sheet is disclosed which is good in tackiness to the skin surface, does not easily dry even when used for a long time, can maintain flexibility, and is small in the shape variation. The skin adhesive sheet includes a copolymer containing the following components A and C as polymerization components, and having a water content less than 10% by mass: component A: a polysiloxane macromonomer having a plurality of polymerizable functional groups per molecule, and having a number average molecular weight of 6,000 or more； and component C: a polymerizable monomer having an alkyl group and having no fluoroalkyl group.
