The object aims to largely improve the productivity of a desired product and maintain an excellent growth rate and an excellent fermentation rate in the production of the desired product by using yeast. A foreign gene which encodes an enzyme involved in the production of the desired product and HAP4 gene which can be expressed constitutively or a homologous gene thereof are introduced into a yeast host. The yeast mutant is preferably a mutant strain having reduced alcohol productivity compared to its wild-type one.