The strength, appearance time, and latitudinal location of the equatorial ionization anomaly (EIA) crest response to the lunar phase are examined using the total electron content of global ionosphere maps during the 18‐year period of 2000–2017. The total electron content of the EIA crest reveals semidiurnal tides with 12.42‐hr period, while the appearance time and latitude of the EIA crests present prominent semimonthly lunar tides of 14.77‐day period. The EIA crests on new/full moon (first/third quarter) lead (lag) those of the overall 18‐year average by about 20–40 min, while the EIA crests move the furthest poleward and equatorward 2–5 days after new/full moon and first/third quarter, respectively. Amplitudes of the semimonthly lunar tide in the EIA crest appearance times and latitudes yield the greatest value around perihelion and the smallest value around aphelion, which shows that the solar declination and seasonal effects are important. Plain Language Summary The most prominent feature in the ionosphere is the equatorial ionization anomaly (EIA), which is characterized by two enhanced plasma crests at low latitudes straddling the magnetic equator. Global ionosphere maps of total electron content are analyzed to see how the ionospheric EIA crests respond to changes in lunar phases and solar declinations. The results show that the EIA crests exhibit prominent semimonthly lunar tides with 14.77‐day period. Appearance times of the EIA crests on new/full moon (first/third quarter) lead (lag) those on the associated overall 18‐year average by about 20–40 min, while the EIA crests move the furthest poleward during new/full moon and equatorward during first/third quarter with the delays of about 2–5 days. These indicate that the lunar phase can significantly modulate the ionospheric EIA. The semimonthly lunar tide in the crest appearance times and latitudes become most prominent around perihelion but the least around aphelion, which shows that the solar declination and seasonal effects are important. Key Points Appearance times of the EIA crests on new/full moon lead those on first/third quarter The EIA crests move most poleward (equatorward) 2–5 days after new/full moon (first/third quarter) The semimonthly lunar tide of the EIA crest becomes most prominent around perihelion