A component assembling apparatus includes an intermittently rotatable index table for holding a plurality of positioning tools for use in positioning components to be assembled, and an index table driving mechanism for intermittently rotating the index table. The apparatus also includes a component feeding device for feeding one of the components and holding the component at a removal position of the device, a tool container for storing the plurality of assembling tools for assembling the components, and an arm robot for removably securing one of the assembling tools at its end. The arm robot is operable to move the component from the removal position of the component feeding device to a predetermined position of the positioning tool on the table, and to assemble the component on the positioning tool. An arm robot driving mechanism is provided for actuating the arm robot and the assembling tool.