A hair curler comprising an elongated substantially hollow hair bobbin includes a PTC heating element having a temperature self-controlling function housed within the hair bobbin. A pair of opposed cup-shaped generally cylindrical members are housed within the bobbin with each cylindrical member including a bottom and a side wall. The heating element is held between the opposed bottoms of the cup-shaped members. Each of the bottoms of the cup-shaped members defines an electrode plate arranged in contact with a respective side of the heating element for transmitting electricity to the heating element and conducting heat from the heating element to the side wall of the respective member. The side wall of each member defines conductors for transmitting the heat to the ends of the hair bobbin. A power supplying pin includes first and second power supplying terminals which are connected to a respective one of the electrode plates. The power supplying pin further includes an insulator interposed between the terminals. One end of the power supplying pin extends in one direction through the heating element and both electrode plates for fastening the heating element and the electrode plates together. Another end of the pin extends in an opposite direction along a longitudinal axis of the hair bobbin toward an open end of the bobbin. The power supplying pin is accessible through the open end of the bobbin and is adapted to be connected to a power source.
