Provided is a transformant of S. pombe mutant which can produce and collect β-glucosidase without requiring complicated separation steps, and a vector which is useful for transforming a yeast of the genus Schizosaccharomyces. The transformant of a S. pombe mutant of the present invention is a transformant of a Schizosaccharomyces pombe mutant which exhibits an increased Gsf activity and decreased or no pyruvyl transferase Pvg1 enzymatic activity, and is comprised of a structural gene sequence encoding a β-glucosidase derived from a filamentous fungus, and a promoter sequence and a terminator sequence for expressing the structural gene in a chromosome or as an extrachromosomal gene. Further, the present invention relates to a cloning vector which is characterized by comprising a hsp9 gene promoter or an ihc1 gene promoter of a yeast of the genus Schizosaccharomyces, and is useful for transforming a yeast of the genus Schizosaccharomyces, an expression vector, a transformant, etc.