A yeast extract containing 0.2% or more of γ-Glu-Abu based on dry weight of the yeast extract is produced by culturing a yeast, such as Saccharomyces cervisiae or Candida utilis, in a medium containing a compound selected from Abu (L-2-aminobutyric acid) and γ-Glu-Abu (L-γ-glutamyl-L-2-aminobutyric acid), and preparing a yeast extract from the obtained cells.