To provide a biological adhesive sheet which is reduced in the influence on living tissue and thus has improved safety. A biological adhesive sheet includes a substrate formed of a biocompatible material； and a plurality of projections that are formed of a biocompatible material and configured so as to protrude from the surface of the substrate. The biological adhesive sheet is bonded to living tissues by the van der Waals force by having the plurality of projections in contact with the living tissues.
