Methods for producing a glow plug having a housing, a ceramic glow pin and a protective tube from which a section of the glow pin projects which is thinner than a thicker section arranged in the protective tube. The thinner section leads to a glow tip. The glow pin is inserted into the protective tube and the protective tube is inserted into the housing. A securing element is placed onto the first end of the glow pin. The internal diameter of the securing element is smaller than the maximum diameter of the glow pin. The securing element is fastened on the protective tube. Alternatively, the protective tube is heated locally at a section of the protective tube surrounding the thinner section, and there the interior width of the protective tube is reduced to a value smaller than the diameter of the thicker section of the glow pin.

A manufacturing method of a ceramic heater-type glow plug including: a ceramic heater; and a metallic outer cylinder, one end of which holds the ceramic heater and the other end of which is fixed to a housing has: a step of forming a metallized layer on at least a portion of a surface region in the ceramic heater that is held by the outer cylinder; a step of press-inserting at least the metallized layer of the ceramic heater in the outer cylinder; and a step of heating the ceramic heater and the outer cylinder at a temperature at which a material for forming the metallized layer becomes a semi-molten state and performing joining by mass transfer between the outer cylinder and a solid layer of the metallized layer.