Tangential flow ultrafiltration with a polyethersulfone (100 kDa) membrane was used for the purification and concentration of ${eta}$-glycosidases (${eta}$-galactosidase and ${eta}$-glucosidase) from aqueous extract of barley. The performances of mode 1 (concentration followed by diafiltration) and mode 2 (diafiltration followed by concentration) were compared. In mode 1 activity recoveries of 91.44 and 88% as well as purifications of 1.84 and 1.77-fold for ${eta}$-galactosidase and ${eta}$-glucosidase, respectively, were obtained in a total processing time of about 9 h. In mode 2 activity recoveries of 95.68 and 91.76% with purifications of 4.56 and 4.38-fold for ${eta}$-galactosidase and ${eta}$-glucosidase, respectively, were obtained in a total processing time of about 6 h. The removal of total carbohydrates and protein was 56.74 and 50.73%, respectively, in mode 1, whereas it was 81.46 and 79.04%, respectively, in mode 2. The diafiltration volume and volume concentration of 3 were maintained in both mode 1 and 2. Flux decline was severe in mode 1 and led to a long processing time of about 9 h. These results indicate that mode 2 was better than mode 1 for purification of ${eta}$-glycosidases.