A configuration in which fixing is performed by inserting a rear end of a lead shaft member into an attachment hole of an external terminal at the rear of a glow plug and crimping an outer peripheral face of the external terminal. The outer peripheral face of a crimp formation region (78) of the external terminal (70) having a polygonal cross section is formed into a crimped portion (79) provided by round crimping toward a circle, and the external terminal (70) is fixed to the rear end (55) of the lead shaft member (50). Due to the configuration obtained from the round crimping of the polygon, plating breaks and the like are not easily produced in the plating layer on the surface of the external terminal.