PURPOSE: To produce a processed meat product of high quality in a high residual ratio of 5'-ribonucleotides added, by coating the 5'-ribonucleotides with oil or fats and adding the coated said nucleotides to a meat.

CONSTITUTION: When a processed meat product such as meat sausage, meat ham, etc., to which 5'-ribonucleotides such as 5'-inosinic acid salt, 5'-guanylic acid sat, etc. are added according to an ordinary method is produced, a phosphatase activity of a raw material before heating and heating condition are controlled so that the area of curve changing with time of phosphatase activity during heating process found from the equation (1) and (2) wherein V0 is degradation velocity at 30°C, VT is initial velocity of degradation at T°K, Ax/A is residual activity, T is absolute temperature and X is time (min) is ≥3.1 and 5'-ribonucleotides coated with solid oil or fats is added to a meat.