Abstract: A multiwave optical buffer using a loop mirror of the present invention can transmit cells to a preferable node in accordance with electric control, without causing conflicts among the cells, when the cells having various waves reach a single node at the same time on a high-speed network. In order to prevent conflicts among the cells, the multiwave optical buffer using the loop mirror in accordance with the present invention stores cells having low priority and outputs the cells in a preferable time pursuant to the electric phase control, thereby improving efficiency of a high-speed optical communication network.