Disclosed is a cable-type secondary battery including an inner electrode including an inner current collector and an inner electrode active material layer formed surrounding an outer surface of the inner current collector, a separation layer formed surrounding an outer surface of the inner electrode to insert the inner electrode inside, an outer electrode active material structure formed surrounding an outer surface of the separation layer to insert the separation layer inside, the outer electrode active material structure including a porous polymer support and an outer electrode active material layer formed on at least one of an upper surface and a lower surface of the porous polymer support, and an outer electrode including an outer current collector formed surrounding the outer electrode active material structure to insert the outer electrode active material structure inside.