The aim of this research was to determine the effect of glucomannan starch from Gembili tuber to the physical and sensory characteristics, and obtaining the right amount of glucomannan flour from Gembili tuber concentration to produce ice cream with good qualities and preferred by the panelists. This study was designed using a Completely Randomized Design (CRD) with one factor, namely the variation ratio of glucomannan flour of Gembili tuber (0%, 0.1%, 0.2%, 0.3% and 0.4%), with three replications in each treatment. The results showed that the addition of glucomannan flour of Gembili tuber at various concentrations significantly affect the lightness (L), hardness, overrun, and the melting speed of ice cream, and the sensory characteristics of ice cream which consists of color, flavor, taste, hardness and overall. The best treatment was ice cream with a 0.3% addition of glucomannan flour, with an average effectiveness value of 0.80.