An optical waveguide plate for a surface light emitting apparatus and a surface light emitting apparatus using the optical waveguide plate that provides excellent uniformity in surface emission is disclosed. The optical waveguide plate comprises an end face introducing light emitted from a light source, and a light emitting surface outputting light introduced from the end face. The end face has a light introducing portion comprising a plurality of notched prisms which disperse incident light. The intervals between two adjacent prisms are set to become greater in proportion to the distance from the center of the light introducing portion. The angles of the prisms are also adjusted to provide uniform surface emission.