We investigate characteristics and generation process of surface waves excited on a structured perfect conductor surface in order to clarify the mechanism of resonant transmission in metal hole arrays made of the perfect conductor. By using a metal hole array of kagome lattice, we can separate two modes excited on the perfect conductor surface; a surface wave and an edge mode. Our calculation based on finite-difference time-domain method provides a generation process of the edge mode and the surface wave that is responsible for the resonant transmission in metal hole arrays.