Abstract: A PTC device which surely achieve effective space utilization while easily excluding the possibility of the formation of a short circuit. The PTC device includes a PTC component 3 comprising a first electrode 11, a second electrode 13, and a PTC element 9 disposed between these electrodes, a first electrically conductive lead 15 which is connected to the first electrode and able to connect with a button terminal of a battery, a second electrically conductive lead 18 which is connected to the second electrode, and an insulating element 23. The insulating element covers the inner periphery 7 of the PTC component, the second electrode and a portion of the second electrode and the second electrically conductive lead on the second electrode.