The present invention provides a novel artificial match-type miRNA that uses miRNA. The artificial match-type miRNA is a single-stranded nucleic acid comprising an X region and a Y region and is configured such that: the 3'-end of the X region and the 5'-end of the Y region are connected via a linker region having a non-nucleotide structure; the X region comprises a mature miRNA guide strand sequence; and the Y region is a single-stranded nucleic acid comprising a sequence that is completely complementary to the X region. This artificial match-type miRNA makes it possible to inhibit the expression of a target gene.