The bitterness of not only foods but also pharmaceuticals has been successfully quantified using taste sensor, which has now been practically used to evaluate the bitterness of pharmaceuticals. Most pharmaceuticals have strong bitterness, and enhancing the medication compliance by patients is an important task for pharmaceutical manufacturers. The taste of a sample prepared by mixing bitternessmasking materials used to suppress bitterness, i.e., sucrose, α-cyclodextrin, BMI-40 (Kao Corporation, Japan), with a bitter substance, in this case quinine chloride, was measured using taste sensor. The results highly correlated with the results obtained from sensory evaluation by sensory panelists, indicating the applicability of taste sensor to the detection of the effect on suppressing the bitterness of pharmaceuticals. Orally disintegrating tablets (ODTs) attracted much attention approximately 20 years after the start of their research and development and 10 years after commercialization. In particular, the use of ODTs has been rapidly promoted since 2000 and has been becoming the mainstream of oral medication. Harada et al. evaluated the bitterness of a carrageenan-containing propiverine hydrochloride ODT . For ODTs containing pectin, agar, or λ-, ι-, or κ- carrageenan, the intensity of bitterness at the complete disintegration was measured using taste sensor and compared with the results of sensory evaluation by panelists, showing a strong correlation with a high correlation coefficient of R = 0.907. Moreover, propiverine hydrochloride eluted from these ODTs was sampled for different elution times and the intensity of bitterness was measured, demonstrating that the time dependence of the change in bitterness intensity can be evaluated using taste sensor.