[Problems] The object of the invention is to provide a process for producing fermented milk having a satisfactory level of harness and smooth texture. [Means of solving the problems] It is found that fermented milk having a satisfactory level of hardness as well as extremely smooth texture can be produced by deoxidizing (deaerating) a yogurt mix, subjecting the deoxidized (deaerated) product to an UHT processing, and then fermenting the resulting product. Specifically disclosed is a process for producing a fermented milk, which comprises a first deoxygenating step for decreasing oxygen concentration in yogurt mix a ultra high temperature sterilization step for heating the yogurt mix after the first deoxygenating step for longer than 1 second at higher than 110 degrees Celsius so as to sterilize the yogurt mix and a fermentation step for fermenting the yogurt mix after the ultra high temperature sterilization step.