A novel joint angle estimation method is proposed using a new bio-signal for an amputee subject. We used the muscle bulge movement on the forearm skin surface as a new bio-signal for estimating the extent of motion in a previous study. We found that it is feasible to estimate the intended wrist joint angle using the distribution of the muscle bulge for intact subjects. Thus, in the present paper, we validate the feasibility of our method for an amputee. In applying our method to an amputee subject, we improved our distance sensor device so that it can accommodate the position of the muscle, which is variable for an amputee subject. In addition, we improved the algorithm that estimates the wrist joint angle using linear multiple regression for calculating the relationship between the intended wrist joint angle and the distribution of the muscle bulge. As a result, we found that the distribution of the muscle bulge changes for the amputee as for intact subjects. The movement of the position of the muscle bulge on the forearm skin corresponded to the extent of the intended wrist joint angle. According to the result of the estimation of the wrist joint angle, the root-mean-square error of the estimated angle with respect to the measured angle for the amputee was slightly larger than the error for intact subjects. Nevertheless, the root-mean-square error for the amputee was smaller than that when employing the previous method for intact subjects. Finally, it is feasible to use the muscle bulge movement on the forearm skin to estimate the intended wrist joint angle for the upper limb amputee.