The invention provides a surface plasmon filter and relates to a filter. The filter is provided with at least one surface plasmon-based groove waveguide; the surface plasmon-based groove waveguide is provided with a metal film; two parallel metal strips are arranged on the upper surface of the metal film; all metal strips of the surface plasmon-based groove waveguide are arranged on the same metal film; an open rectangular cavity is formed in the cross section of the surface plasmon-based groove waveguide; and except for the metal film and the metal strips, the other parts of the surface plasmon-based groove waveguide are mediums. By the cut-off characteristics of the surface plasmon-based groove waveguide, the surface plasmon filter is achieved; and the surface plasmon filter not only has good wavelength selection transmission characteristics on surface plasmons, but also is simple in structure, small in dimension, low in cost, easy to process and very suitable for integration.