The invention provides a block polymer capable of being used as a molecular wire facilitating injection of carriers between itself and an electrode, and a device in which electrodes are bridged by one molecule. The block polymer has a main chain composed of polyacetylene having a spiral structure, and includes a coating insulating block and a conductive block. The coating insulating block has a polyacetylene unit structure having alkyl chains at its side chains through functional groups, the alkyl chains being arranged in a direction parallel to the major axis of the main chain. The conductive block has a polyacetylene unit structure having hydrogen atoms at its side chains through functional groups, the hydrogen atoms being arranged in a direction parallel to the major axis of the main chain. The device has the above-mentioned block polymer, and two or more electrodes.