Disclosed is the structure of a center pin assembly inserted into the winding center of a winding-type electrode assembly of an electrochemical device, which has a case containing the winding-type electrode assembly. The center pin assembly can secure the safety of an electrochemical device when physical impact (e.g. squeezing, shock) is applied from the outside, when the internal temperature rises, and/or when the device is overcharged. The center pin assembly includes a center pin manufactured by winding a planar substrate into a tubular shape, the planar substrate having at least two protrusions formed in an embossing type or at least two discontinuous scores formed in a predetermined shape; and a container placed in a space inside the center pin, the container containing a substance capable of improving the safety of the device.