The problem to be solved by the present invention is to provide an isoprenoid production method with which it is possible to produce isoprenoids such as ascofuranone, ilicicolin A, ascochlorin and derivatives thereof in higher yields than conventional techniques, and thereby to enable industrial-scale production of isoprenoids. The problem is solved by a method for producing an isoprenoid such as ascofuranone, ilicicolin A or ascochlorin, the method comprising a step of obtaining an isoprenoid such as ascofuranone, ilicicolin A or ascochlorin using a transformant transformed with a biosynthesis gene for ascofuranone, ilicicolin A or ascochlorin, or a knockout organism thereof.