[Problem] To provide a sweetness and/or milk flavor enhancer which can increase the sweetness and/or the milk flavor of a cooked product and therefore enables the reduction of the amount of a sweetening agent and/or a milk flavor additive to be used. [Solution] The sweetness and/or milk flavor enhancer according to the present invention contains an oxidized and partially hydrogenated oil or fat having a peroxide value of 25 to 300 as an active ingredient. The content of a trans fatty acid in the oxidized and partially hydrogenated oil or fat is preferably 5 to 75 wt%. The iodine value of the oxidized and partially hydrogenated oil or fat is preferably 35 to 135.