An object of the present invention is to provide ASO that can effectively suppress a formation of RNA foci spontaneously occurring in neurons having SCA36 mutation, without inducing the cleavage of NOP56 pre-mRNA. The present invention provides an oligonucleotide comprising a nucleotide sequence in which one or more nucleotide sequences represented by SEQ ID NO: 2 are consecutively connected and is complementary to pre-mRNA of NOP56 gene, wherein a structure formed by the hybridization of the oligonucleotide to the pre-mRNA is resistant to RNaseH.