A method of detecting Paecilomyces variotii, comprising the following steps for identification of Paecilomyces variotii amplifying a partial nucleotide sequence of a β tubulin gene by a polymerase chain reaction method using the following oligonucleotides (a) and (b); (a) and (c); or (a), (b) and (c) as nucleic acid primers: (a) an oligonucleotide represented by the nucleotide sequence set forth in SEQ ID NO: 7, or an oligonucleotide represented by a nucleotide sequence which has 95% or more homology to the nucleotide sequence set forth in SEQ ID NO: 7 and can be used as a nucleic acid primer; (b) an oligonucleotide represented by the nucleotide sequence set forth in SEQ ID NO: 8, or an oligonucleotide represented by a nucleotide sequence which has 95% or more homology to the nucleotide sequence set forth in SEQ ID NO: 8 and can be used as a nucleic acid primer; (c) an oligonucleotide represented by the nucleotide sequence set forth in SEQ ID NO: 9, or an oligonucleotide represented by a nucleotide sequence which has 95% or more homology to the nucleotide sequence set forth in SEQ ID NO: 9 and can be used as a nucleic acid primer; and confirming whether the amplified product is present or not, wherein the presence of the amplified product is indicative of Paecilomyces variotii. amplifying a partial nucleotide sequence of a β tubulin gene by a polymerase chain reaction method using the following oligonucleotides (a) and (b); (a) and (c); or (a), (b) and (c) as nucleic acid primers: (a) an oligonucleotide represented by the nucleotide sequence set forth in SEQ ID NO: 7, or an oligonucleotide represented by a nucleotide sequence which has 95% or more homology to the nucleotide sequence set forth in SEQ ID NO: 7 and can be used as a nucleic acid primer; (b) an oligonucleotide represented by the nucleotide sequence set forth in SEQ ID NO: 8, or an oligonucleotide represented by a nucleotide sequence which has 95% or more homology to the nucleotide sequence set forth in SEQ ID NO: 8 and can be used as a nucleic acid primer; (c) an oligonucleotide represented by the nucleotide sequence set forth in SEQ ID NO: 9, or an oligonucleotide represented by a nucleotide sequence which has 95% or more homology to the nucleotide sequence set forth in SEQ ID NO: 9 and can be used as a nucleic acid primer; and (a) an oligonucleotide represented by the nucleotide sequence set forth in SEQ ID NO: 7, or an oligonucleotide represented by a nucleotide sequence which has 95% or more homology to the nucleotide sequence set forth in SEQ ID NO: 7 and can be used as a nucleic acid primer; (b) an oligonucleotide represented by the nucleotide sequence set forth in SEQ ID NO: 8, or an oligonucleotide represented by a nucleotide sequence which has 95% or more homology to the nucleotide sequence set forth in SEQ ID NO: 8 and can be used as a nucleic acid primer; (c) an oligonucleotide represented by the nucleotide sequence set forth in SEQ ID NO: 9, or an oligonucleotide represented by a nucleotide sequence which has 95% or more homology to the nucleotide sequence set forth in SEQ ID NO: 9 and can be used as a nucleic acid primer; and confirming whether the amplified product is present or not, wherein the presence of the amplified product is indicative of Paecilomyces variotii.