The present invention addresses the problem of providing a novel cyclin-dependent kinase 8 and/or 19 inhibitor that is useful as an anticancer agent. The present invention relates to a cyclin-dependent kinase 8 and/or 19 inhibitor that contains, as an active component, a compound expressed by general formula (I) (the definition of each symbol therein being as indicated in the specification) or a pharmaceutically acceptable salt thereof. The present invention also relates to a use of said inhibitor as a cancer preventative and/or therapeutic agent.
