A process for the purification of a neutral human milk oligosaccharide (HMO) in a batch manner or in a continuous manner from a fermentation broth obtained by microbial fermentation using a recombinant microorganism, the neutral human milk oligosaccharide being selected from the group consisting of 2' -fucosyllactose, 3-fucosyllactose, 2',3-difucosyllactose, lacto- N -triose II, lacto- N -tetraose, lacto- N -neotetraose, lacto- N- fucopentaose I, lacto- N -neofucopentaose, lacto- N -fucopentaose II, lacto- N -fucopentaose III, lacto- N -fucopentaose V, lacto- N- neofucopentaose V, lacto- N -difucohexaose I, lacto- N -difucohexaose II, 6'-galactosyllactose, 3'- galactosyllactose, lacto- N -hexaose and lacto- N- neohexaose, said fermentation broth containing the neutral HMO in a purity of < 80 %, biomass, medium components and contaminants selected from the group consisting of monovalent salts, divalent salts, amino acids, polypeptides, proteins, organic acids and nucleic acids, wherein the fermentation broth is applied to the following purification steps: i) separation of biomass from the fermentation broth, ii) cationic ion exchanger treatment for the removal of positively charged material with a cation exchanger in proton form, iii) anionic ion exchanger treatment for the removal of negatively charged material, and iv) nanofiltration step and/or electrodialysis step, wherein a purified solution containing the neutral HMO in a purity of > 80% and being free from DNA and proteins of the microbial fermentation strain is provided. the neutral human milk oligosaccharide being selected from the group consisting of 2' -fucosyllactose, 3-fucosyllactose, 2',3-difucosyllactose, lacto- N -triose II, lacto- N -tetraose, lacto- N -neotetraose, lacto- N- fucopentaose I, lacto- N -neofucopentaose, lacto- N -fucopentaose II, lacto- N -fucopentaose III, lacto- N -fucopentaose V, lacto- N- neofucopentaose V, lacto- N -difucohexaose I, lacto- N -difucohexaose II, 6'-galactosyllactose, 3'- galactosyllactose, lacto- N -hexaose and lacto- N- neohexaose, said fermentation broth containing the neutral HMO in a purity of < 80 %, biomass, medium components and contaminants selected from the group consisting of monovalent salts, divalent salts, amino acids, polypeptides, proteins, organic acids and nucleic acids, wherein the fermentation broth is applied to the following purification steps: i) separation of biomass from the fermentation broth, ii) cationic ion exchanger treatment for the removal of positively charged material with a cation exchanger in proton form, iii) anionic ion exchanger treatment for the removal of negatively charged material, and iv) nanofiltration step and/or electrodialysis step, i) separation of biomass from the fermentation broth, ii) cationic ion exchanger treatment for the removal of positively charged material with a cation exchanger in proton form, iii) anionic ion exchanger treatment for the removal of negatively charged material, and iv) nanofiltration step and/or electrodialysis step, wherein a purified solution containing the neutral HMO in a purity of > 80% and being free from DNA and proteins of the microbial fermentation strain is provided. <EOS>