A conveyer device conveys a component assembly including a female screw component having a through hole defining a female screw, an assembling component to be assembled to the female screw component from above, and a bolt to be screwed to the female screw of the female screw component from above the assembling component to fix the assembling component. The conveyer device also includes a holding member for holding the female screw component and a screwing restriction mechanism for restricting the bolt, held by the assembling component while unscrewed from the female screw, from being screwed to the female screw. Thus, when the component assembly, to which the bolt is temporarily assembled without being engaged with the female screw, is conveyed while being held by the holding member via the female screw component, the bolt is prevented from being unintentionally screwed into the female screw as the result of vibration etc. caused by the conveyance.