The present invention relates to a cable-type secondary battery having a horizontal cross section of a predetermined shape and extending longitudinally, comprising: an inner electrode having an inner current collector and an inner electrode active material layer surrounding the outer surface of the inner current collector; a separation layer surrounding the outer surface of the inner electrode to prevent a short circuit between electrodes; and an outer electrode surrounding the outer surface of the separation layer, and having an outer electrode active material layer and an outer current collector comprising at least one of a conductive paste and a carbon fiber.In accordance with the present invention, the outer current collector which comprises a conductive paste or a carbon fiber to have good flexibility is used in a cable-type battery to improve the flexibility of the cable-type battery.