In recent years, it became possible to manufacture a highly precise and high-strength metal micro gear. However, the systematic evaluation about the load carry characteristics of the micro gear is not reported. Accordingly, we have developed a test equipment which can perform endurance tests of the micro gear easily. Then, we measured the minimum load torque of the developed system and examined the dimensions of the micro gear suitable for the endurance test. Furthermore, we performed acceleration tests using micro gears which were relatively large module and we got some knowledge. In this study, as basic research of the endurance test of the micro gear, we examined the effect of the lubricating oil on the load carrying characteristics of the micro spur gear. Specifically, we used two types of lubricating oil, and we performed acceleration tests of the micro spur gear under wide range of rotational speed and relatively low load torque condition. The lubricating condition is dropping of the lubricating oil of only at the time of experiments start. While the acceleration tests, we observed the condition of the tooth surface and volume of the lubricating oil. Then, we examined the effect of lubricating conditions and properties of the lubricating oil on the condition of the tooth surface of the micro spur gear. As the result, we obtained the following results; (1) The meshing teeth of damaged test gears in the lubricating oil dropping conditions, scattering of the lubricating oil is great influence. Therefore, the performance of the lubricating oil in the lubricating oil dropping conditions, scattering difficulty in high rotational speed is one of the important factors. (2) In the range of the conditions in this study, low viscosity turbine oil showed a better performance.