The present invention provides a method of producing a yeast extract with a high nucleic acid content from yeast cells. The method of producing a yeast extract of the present invention includes: (1) a step of subjecting yeast cells to a heat sterilization at 100 to 130°C for 10 to 90 seconds, (2) a step of preparing a yeast extract by subjecting the yeast cells sterilized in step (1) to an extraction treatment at 50 to 85°C and a pH of 7 to 10, (3) a step, performed after step (2), of subjecting the obtained yeast extract to a solid-liquid separation treatment to remove at least a portion of the insoluble matter, (4) a step, performed after step (3), of subjecting the yeast extract from which the insoluble matter has been removed to a nuclease treatment and a deaminase treatment, and (5) a step, performed after step (4), of subjecting the yeast extract to a heat sterilization treatment.