PROBLEM TO BE SOLVED: To provide a method for manufacturing Salicornia herbacea powder extracted by high- pressure hot water excellent in functionality and processing suitability, while utilizing an active ingredient of the Salicornia herbacea to the maximum, and to provide a method for manufacturing Miso. SOLUTION: The method for manufacturing the Salicornia herbacea powder extracted by the hot water includes: a Salicornia herbacea drying stage of dying raw Salicornia herbacea; a high-pressure hot water extraction stage of introducing water into the dried Salicornia herbacea and extracting with the hot water for 4-8 hours at 130-150°C; a low-temperature aging stage of adjusting the concentration of the extracted solution at Brix 3-6, and aging the extracted solution for 2-5 days at 1-8°C; and a high-temperature spraying and drying stage of spraying the aged extracted solution to a disk rotating at 12,000-18,000 rpm in a chamber of a powder dryer where the temperature is kept at 220-330°C. COPYRIGHT: (C)2012,JPO&INPIT