embodiments of fig1 and 5 the insulating cylinder 31 surrounds the sub passage 28b and operates as an electrode stand the insulating cylinder 31 is formed from a ceramic material and includes a step portion and a groove a burner cover 33 is disposed about the insulating cylinder 21 as shown referring to fig1 a nut 34 is inserted in the groove between the burner cover 33 and the insulating cylinder 31 to act as a rotational stop and retainer for the burner cover 33 the burner cover 33 of fig1 also includes a protruding discharge electrode 32 which acts as a latch member by engaging the step portion of the internal cylinder 31 the burner cover 33 is connected to a lead wire 37 of a piezoelectric ignition device 36 provided on the body 1 as shown in fig2 the connection between the lead wire 37 and the burner cover 33 can be easily achieved by inserting the end portion of the lead wire 37 into the clearance between the insulating cylinder 31 and the burner cover 33 the end portion of the lead wire 37 is then connected to the burner cover 33 in the embodiment shown in fig5 the insulating cylinder 31 includes a coaxially formed recess 31a the insulating cylinder 31 of fig5 also includes a hole 31c extending into a recess 31a and forming an opening 31b at the external end of the insulating cylinder 31 a metal wire 32a one end of which acts as the electrode 32 is inserted into the recess 31a and the hold 31c the end.