A component mounting device includes a controller that controls an imaging unit to image a predetermined region during a period from a time point at which a head finishes mounting a component at a mounting position to a time point at which the head completes upward movement from the mounting position, and acquires information about a height of the mounting position based on an imaging result of the predetermined region imaged by the imaging unit. The controller further determines whether or not the component has been successfully mounted at the mounting position based on the acquired information about the height of the mounting position.