In this research, we had studied the sensitivity for machining of cobalt-based superalloy Haynes 188 with ceramic cutting tool. The investigation had focused on the effects of the cutting speed, on the cutting forces, and on the surface roughness based on Taguchi's experimental design. The effects of machining parameters were determined using Taguchi's L27 orthogonal array. The signal-to-noise ratio was calculated for the average of surface roughness and the cutting forces, and the smaller were used to determine the optimal cutting conditions. The analysis of variance and the signal-to-noise ratio had effects on the parameters on both surface roughness and cutting. Three different types of cutting tools had been used in the experiment, namely KYON 4300, KYS 25, and KYS 30. The cutting force of Fz was considered to be the main cutting force. Depending on the material which had been used as cutting tool, the Fz had the lowest cutting speed and the lowest surface roughness with the KYS25 ceramic tool. The cutting force and the surface roughness of KYON 4300 cutting tool had shown better performance than other cutting tools. The flank wear and notch were found to be more effective in the experiments. The long chips were removed at low and medium cutting speeds, while the sawdust with one edge and narrow pitch at high cutting speeds was obtained.