Machining conditions are investigated to improve a tool life in end milling of Cobalt Chromium Molybdenum (Co-Cr-Mo) alloy. First, the machinability of Co-Cr-Mo alloy is estimated by using Difficult-to-Cut Rating (DTCR). To investigate the influence of tool shapes and cutting conditions on material removal rate and volume, cutting experiments are conducted. Experimental results showed that the cutting force increases as the cutting speed increases. Finally, tool life tests are conducted. We experimentally found the machining condition that achieves the material removal rate of 2.16 cc/min and the material removal volume of 391.6 cc or more.