The gamma-ray emission from the Moon comes from the secondary interactions of cosmic-rays with the lunar surface and the flux intensity is therefore linked to the flux of cosmic rays on the Moon. Since the flux of cosmic rays is affected by the solar modulation, we expect to observe higher fluxes at the solar minimum and lower flux levels going toward the solar minimum. Moreover the knowledge of the lunar emission is important for studies of any weak and transient sources near the ecliptic, and therefore the lunar flux has to be studied carefully. In this work the Fermi LAT observation of the observed lunar emission during the first 4 years are presented.