Provided are a seasoning that contains deep and rich flavor of ingredients mainly composed of a large amount of glutamic acid, and a method for producing the seasoning. The glutamic acid content in a glutamic acid containing seasoning liquid thus produced is not lowered even after long-term storage thereof. Herein, a protein raw material such as wheat gluten, defatted soybeans, and an extracted residue of dried and fermented fish shavings is enzymatically decomposed by the liquid koji. In that step, a zinc containing compound or zinc yeast is added to the mixture of the raw materials such that the zinc concentration is set in the range from 5 ppm or more to 700 ppm or less as a conversion amount of pure zinc. This procedure facilitates the enzymatic decomposition to produce an excellently flavored seasoning liquid or powder including a large amount of glutamic acid.