The purpose of the present invention is to provide a component mounting method, and a component mounting device provided with multiple mounting lanes wherein, when the substrate type is changed, the component mounting device is capable of performing a device type switching operation without stopping operation of the mounting lane in production and without compromising operator safety. A component mounting device (1) provided with a first mounting lane (L1) and a second mounting lane (L2) is capable of selecting an independent mounting mode and an alternating mounting mode, wherein, in the independent mounting mode, a first mobility limit region (R1A) and a first mobility limit region (R1B), where a first mounting head (13A) and a second mounting head (13B) of each lane can move in the horizontal direction, are set to be different from second mobility limit regions in the alternating mounting mode, and the mounting head of the mounting lane which is continuing production does not enter the region of the mounting lane which is in the process of the device type switching operation.