The invention relates to a glow plug and methods for the production thereof. According to the invention, said glow plug is made from an electrically conducting and an electrically nonconducting element, sintered composite ceramic material being used for the production thereof. The disclosed glow plugs can preferably be used for fuel-operated auxiliary heaters of motor vehicles. The aim of the invention is to be able to produce said glow plugs in an inexpensive and flexible manner while providing the same with a longer service life and greater resistance to oxidation. Said aim is achieved by surrounding two opposite sides of the conducting element with the electrically nonconducting element while providing the conducting element with an expanded cross-section in the distal area, the ratio of the expanded cross-section to the cross-section of the electrically conducting element ranging between 2.5 and 5 to 1. Sixty to 85 percent of the surface of the proximal heating area of the electrically conducting element, which has a reduced cross-section, are covered by the material of the electrically nonconducting element.