LHCf is a high-energy physics experiment designed to study the forward production of neutral particles in proton–proton collisions at the LHC. The set-up consists of two small calorimetric systems symmetrically placed 140m away on both the sides of the ATLAS interaction point. Results from the experiment will provide valuable information to the calibration of the nuclear interaction models used in the Monte Carlo codes for air-shower simulations, which are of great importance for present and future ground-based cosmic-ray experiments. In particular, since LHCf will start taking data in the first phase of operation of the LHC (during the beam commissioning phase at 5+5TeV energy) and will complete its data taking at the beginning of the 7+7TeV runs (laboratory equivalent collision energy 1017eV), it will span an energy range up to the region between the “knee” and the GZK cut-off of the cosmic-ray spectrum.