A method for regenerating silicon from silicon waste includes: placing and mixing silicon waste, a solvent having pH of approximately 5 to approximately 6, and a surfactant within a container; and injecting air into the container to separate floating matters and precipitates. Accordingly, since silicon is easily separated from the silicon waste, the regeneration yield of silicon is increased. Since the regenerated silicon is recyclable, it may be possible to obtain important substitution effect of high-purity silicon the entire amount of which depends on import. Moreover, environmental pollution may be reduced because the amount of the silicon waste disposed of by burial is decreased.