The present invention relates to a method for expressing a target protein on an exosporium forming the outermost surface of bacterial spores. More particularly, the present invention relates to a method for expressing a target protein on the surface of cells and spores using an exosporium as a matrix for surface expression, and methods for the production of a protein array, the production of antibodies, the separation of a certain substance from a mixture, bioconversion, and the improvement of a target protein, which are characterized by using the cells or spores having the target protein that was expressed on the surface by the above expression method. The method for expressing the target protein on the surface of the spore outer membrane of the gene carriers according to the present invention has effects in that a variety of the target proteins can be expressed and the level of surface expression of the target protein is increased compared to the existing technology, and also the structural stability of the gene carriers having the target protein expressed on their surface, the viability of the host, and the rapidity of the screening method, are greatly increased.