A review of measurements of the muon energy spectra for different altitudes, height and directions performed with devices placed at various geomagnetic latitudes is presented. The theoretically motivated final fit to the existing experimental differential and integral data will be presented. The muon spectra and the muon charge ratio, defined as the ratio of positive to negative muon fluxes, are analysed taking into account the geomagnetic field, in view of the East-West effect. Fluxes of bouth possitive and negative muons are analysed.

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 5 (HE part 2), pages 1257-1260