A method of preparing a complex fluoride phosphor having the formula: A 1 2 MF 6:Mn wherein M is at least one tetravalent element selected from Si, Ti, Zr, Hf, Ge and Sn, and A 1 represents at least one alkali metal selected from Li, Na, K, Rb and Cs, provided that A 1 includes Na and/or K; said method comprising the steps of: providing a first solution containing a fluoride of tetravalent element M, hydrogen fluoride and water; providing a compound of alkali metal A in a second solution consisting of the compound of alkali metal A and water, and/or a compound of alkali metal A in solid form, A representing at least one alkali metal selected from Li, Na, K, Rb and Cs and the compound of alkali metal A being selected from fluorides, hydrogenfluorides, nitrates, sulfates, hydrogensulfates, carbonates, hydrogencarbonates and hydroxides of A; adding at least one of the manganese compounds Na 2 MnF 6 and K 2 MnF 6 to the first solution; mixing the first solution with said second solution and/or said solid for reacting the fluoride of tetravalent element M with the compound of alkali metal A and with the manganese compound, to form a solid product, and recovering the solid product via solid-liquid separation. M is at least one tetravalent element selected from Si, Ti, Zr, Hf, Ge and Sn, and A 1 represents at least one alkali metal selected from Li, Na, K, Rb and Cs, provided that A 1 includes Na and/or K; said method comprising the steps of: providing a first solution containing a fluoride of tetravalent element M, hydrogen fluoride and water; providing a compound of alkali metal A in a second solution consisting of the compound of alkali metal A and water, and/or a compound of alkali metal A in solid form, A representing at least one alkali metal selected from Li, Na, K, Rb and Cs and the compound of alkali metal A being selected from fluorides, hydrogenfluorides, nitrates, sulfates, hydrogensulfates, carbonates, hydrogencarbonates and hydroxides of A; adding at least one of the manganese compounds Na 2 MnF 6 and K 2 MnF 6 to the first solution; mixing the first solution with said second solution and/or said solid for reacting the fluoride of tetravalent element M with the compound of alkali metal A and with the manganese compound, to form a solid product, and recovering the solid product via solid-liquid separation. providing a first solution containing a fluoride of tetravalent element M, hydrogen fluoride and water; providing a compound of alkali metal A in a second solution consisting of the compound of alkali metal A and water, and/or a compound of alkali metal A in solid form, A representing at least one alkali metal selected from Li, Na, K, Rb and Cs and the compound of alkali metal A being selected from fluorides, hydrogenfluorides, nitrates, sulfates, hydrogensulfates, carbonates, hydrogencarbonates and hydroxides of A; adding at least one of the manganese compounds Na 2 MnF 6 and K 2 MnF 6 to the first solution; mixing the first solution with said second solution and/or said solid for reacting the fluoride of tetravalent element M with the compound of alkali metal A and with the manganese compound, to form a solid product, and recovering the solid product via solid-liquid separation.