A method for manufacturing furan-2,5-dicarboxylic acid (FDCA) by converting a furan-2,5-dicarboxylate salt (MFDC) into FDCA, including the steps of combining an aqueous solution of MFDC with a concentration of at least 5 wt. % with an inorganic acid (HY), to form a reaction mixture including solid FDCA in a concentration of 1-15 wt. % in a salt solution resulting from the cation of furan-2,5-dicarboxylate salt and the anion of the inorganic acid (MY solution), removing solid FDCA from the reaction mixture in a solid/liquid separation step, and providing part of the MY solution resulting from the solid/liquid separation step to the step of combining MFDC with HY. The step of providing part of MY salt solution resulting from the solid/liquid separation step to the step of combining MFDC with HY makes it possible to obtain a stable and economic process which results in an FDCA product with good quality and high yield.