The present invention relates to a protein having the amino acid sequence represented by SEQ ID NO: 1, or a protein having ferulic acid decarboxylase activity and having an amino acid sequence wherein one or more amino acid residues are deleted, substituted or added in the amino acid sequence represented by SEQ ID NO: 1; a gene encoding said protein; a recombinant vector comprising said gene; a transformant carrying said recombinant vector; a process for producing 4-vinylguaiacol, vanillin or vanillic acid, or a distilled liquor, wherein an enzyme source having ferulic acid decarboxylase activity which is derived from said transformant is used; and a process for producing a distilled liquor, wherein yeast having an enhanced ferulic acid decarboxylase activity is used.