Carbon fiber reinforced plastic (CFRP) has been widely used to build aerospace parts due to light weight and high stiffness. CFRP plate is formed by a multilayer stack which consists of highly brittle carbon fiber and polymer matrix having different material properties with respect to the temperature. After the forming process, additional routing process is performed to obtain the designed part with better geometric accuracy and surface quality. In the CFRP routing process, surface defects, such as fiber pullout and delamination, are affected by the process temperature. This is due to the temperature-sensitive properties of the polymer matrix. Moreover, bending of carbon fiber changes due to the stiffness of the carbon fiber that is modified with temperature. Therefore, machining temperature should be investigated to reduce the defects during the CFRP routing process. In this study, a routing-machined surface was analyzed with respect to the spray pressure of the liquid nitrogen which can change the machining temperature. Various coolant pressures were applied. As a result, the surface roughness of cutting surface was studied and compared to that of the conventional dry machining. Moreover, cooling pressure was proposed to improve the surface quality of the CFRP routing process.