Nanopowders of strontium fluoroapatite Sr5(PO4)3F (SFAP) were synthesized using a co-precipitation method with different starting strontium compounds. Based on the data of XRD, BET and SEM measurements, the nitrate-derived powders were chosen as the least agglomerated. The SFAP powders were hot pressed at 1000 °C to ceramic samples with a transmittance up to 82% in a mid-IR region. The designed approach was adopted to prepare 2 mol % of Er-doped SFAP powders and ceramics. It was established that Er:SFAP ceramics have luminescence in the range of 1.5–1.7 μm, the intensity of which increases with the calcination temperature of the initial powders.