To arbitrate an entire line with a simple configuration in a line system in which plural control units connected to the processors of respective works are connected to each other through a network.

Plural control units 4-1 to 4-N connected to respective processors and conveyers are connected to each other through a sequencer network 3 and the entire line including buffers is controlled by this line controller 1. Besides, information on the works and the conveyance of works and information on the states of respective processors are stored in a storage device 2 and each of control units is provided with a shared memory sharing the information on the line state between the buffer connected to the arbitrary control unit and the buffer connected to the downstream side control unit on the basis of that stored information. On the basis of information in the shared memory, line operation is controlled.