The increasing use of fossil fuels causes a high demand for fossil energy sources, which in addition to being unfriendly to the environment, causing air pollution, are also non-renewable. Therefore, renewable alternative fuels are needed. One alternative fuel is bioethanol, where biobutanol can be made from cassava peel raw materials using hydrolysis and fermentation methods. Cassava peel contains starch which can be converted into glucose by hydrolysis process using HCl catalyst and then fermented with Saccharomyces cerevisiae microorganisms to produce bioethanol. The experimental results show that the bioethanol content that meets the standards as a fuel mixture is the result of hydrolysis with 26% glucose using a 25% HCl catalyst, the bioethanol content before distillation is 17.11% and after distillation 66.13% on the 10th day of fermentation as best result. The results of the GC-MS (Gas Chromatography – Mass Spectrometry) test showed that bioethanol has a wavelength that may indicate the presence of OH- functional groups or hydrogen bonds from bioethanol raw materials.