An IRBT(Inner Race Ball Track)-grinding machine has been developed as a factory-specific equipment for the precision grinding of surfaces on the inner race ball tracks for CV(Continuous Velocity)-joint. The machining accuracy of the grinding machine for securing product quality is most affected by the strength and rigidity of its support structure. For this purpose, static and dynamic behaviors of the grinding machine should be evaluated before the initial design stage, and also the shape optimization of internal ribs in the support structure should be required. In the present study, structural and modal analysis were carried out to estimate the rigidity of the support structure for the IRBT-grinding machine by taken into account of its static- and dynamic compliances. The obtained numerical results provided major information to determine if the requirement of design criteria for the IRBT-grinding machine were met. (Business for Cooperative R&D between Industry, Academy, and Research Institute funded Korea Small and Medium Business Administration in 2017, S2455569)