A glow plug includes: a tubular body (2) having at one of its ends a plug head (10) as well as a zone for being fixed into a bore, an arm (4) mounted on the body (2) of the plug at the end opposite to the plug head (10), and secured to the body (2) in a linking zone (16), an elastically deformable portion (18), located between the linking zone (16) with the arm (4) and the zone fixing the plug body (2), such that the linking zone (16) is mobile and can move longitudinally relative to the so-called stationary fixing zone, and a pressure sensor (8) arranged between an element (30) secured to the linking zone (16) and a fixed element (20) of the plug.