Batch and continuous cell retention cultures were carried out using tapioca hydrolysate. In batch culture, reducing sugar of about 180g/$ell$ was almost consumed in about 36 hours, and the concentration of ethanol produced was about 84g/$ell$ making the ethanol yield 0.48 g-ethanol/g-(reducing sugar). The final yeast concentration was 8.5${ imes}$107 cells/ml(about 2.1g/$ell$). In a total cell retention culture operated with a dilution rate of 0.18h-1, the yeast concentration, the residual reducing sugar concentration, the ethanol concentration, and the volumetric ethanol productivity were about 40g/$ell$, about 15g/$ell$, 81.4g/$ell$, and 14.7g/$ell$-h, respectively. In another cell retention culture operated with a dilution rate and a bleed ratio of 0.2h-1 and 0.14, respectively, the yeast concentration increased to 22g/$ell$ and the ethanol concentration oscillated around 68g/$ell$. The volumetric ethanol productivity was about 13.6g/$ell$-h and the residual reducing sugar concentration about 12g/$ell$ containing glucose of about 4.5g/$ell$. According to the results of batch fermentation using the solid residue from hydrolysate filtration as the substrate, it seemed to have a certain value. Thus, development of an effective reactor system to produce ethanol from this solid residue is in need.