Abstract: A rack of a yogurt machine is disclosed. The yogurt machine includes a main body, which has a surface to which a controller is mounted and is recessed to form an accommodation compartment for receiving a blower assembly mounted therein and in connection with the controller. At least one rack is mounted atop the main body and includes, at a lower portion thereof, a lower rack frame that is stacked on and coupled to the main body. The lower rack frame has an inner surface on which coupling projections are mounted and is coupled, with a top thereof, to an upper rack frame that is inwardly contracted with respect to and extends upward from the lower rack frame. The upper rack frame receives a horizontal support board therein and includes yogurt fermentation cups mounted thereto. A top cover is fit to a top rim of the upper rack frame.