In this study, temperature of cutting tool in high-speed milling was simulated using finite element method, and then the influences of cutting conditions and cutting edge geometry on tool temperature were studied. It was found out that a rapid temperature change is repeated in intermittent cutting, and the temperature around the cutting edge becomes very high within very short time. Combination of feed rate and radius depth of cut has a large influence on tool temperature. Thus it was suggested that maximum tool temperature becomes lower under the condition of high cutting speed and small radial depth of cut when the equal material removal rate is assumed. Also it was shown that the tool geometry such as rake angle and helix angle affect on tool temperature.