Abstract: A waveguide shield for containing electromagnetic interference (EMI) is disclosed. The waveguide shield includes an array of waveguide cells. Each waveguide cell has a contiguous inner surface coated with an absorber layer that absorbs EMI over a select frequency range. Each waveguide cell also has an aperture. The waveguide shield can be combined with a metallic chassis covering portions of a computer that generate the EMI and heat. The absorber layer allows the waveguide cells to have apertures of a size that can contain the EMI within the chassis while also allowing the heat trapped within the chassis to escape.