The invention concerns an ignition device for internal combustion engine,
containing: a main chamber (1) designed for including a main
combustible mixture, and fitted with a compression system of said
mixture, and an igniter (11) containing a precombustion chamber (2)
designed for receiving reactants and an ignition system (13,14) of the
reactants contained in the precombustion chamber (2), said precombustion
chamber (2) being defined by a precombustion chamber body (12) having a
head (12a) including at least one passageway (15), said head (12a) of the
precombustion chamber body separating the precombustion chamber (2) from
the main chamber (1) and communicating the precombustion chamber (2) and
the main chamber (1) by dint of the passageway(s) (15), characterised in
that the head (12a) is coated at least partially externally with a
coating layer (R) of at least one refractory material.