We have fabricated a two‐dimensional photonicband structure based on macroporous silicon with individual gaps for both polarizations in the infrared region between 250 and 500 cm−1 (20–40 μm). A square lattice of circular air rods with a lattice constant of 8 μm was etched 340 μm deep in an n‐type silicon substrate by electrochemical pore formation in hydrofluoric acid. The transmission spectra between 50 and 650 cm−1 were in good agreement with the theoretical calculated structure. The pore formation technique should allow the fabrication of photonic lattices with a complete two‐dimensional band gap in the middle and near infrared.