To provide a method and a device for producing essence of mushroom and mushroom mycelium having antioxidation effect, strong essence extracting power and high quality without the need of antiseptic.

This method for producing the essence of mushroom and mushroom mycelium comprises introducing wave water into a culture tank 21 with a first extremely high-temperature heat treatment device 10, stirring and mixing with the wave water an essence extraction material (A) of e.g. mushroom mycelium which is put into a cloth filter 28 in a meshy container 26 in the culture tank 21 while aerating from the two up and down directions so as to extract the essence of the essence extraction material (A) while culturing the essence. Furthermore, the method comprises introducing the product into a heating sterilization tank 40, heating with aeration the product to perform sterilization treatment of various bacteria in liquid and eliminating treatment of suspended matters, introducing the product into a second extremely high-temperature heat treatment device 51 to subject thermophilic bacteria (spore germ) in liquid to sterilization treatment, introducing the product into a storage tank 59 to subject the product to ripening treatment with aeration, and storing the product up to shipment.