A component mounting apparatus includes two board transfer devices each for transferring boards, at least one component supply device for supplying plural kinds of components to be mounted on the boards, and a component placing device including at least one component placing head for picking up the supplied components to mount the picked-up components on the boards and at least one head moving mechanism for moving the at least one component placing head in at least two directions parallel to a surface of the board. The apparatus also includes a controller that operates one component placing head to mount components alternately on two boards transferred by the two board transfer devices to respective component mounting positions and operates two component placing heads to mount components in parallel on two boards transferred by the two boards transfer devices to the respective component mounting positions.