The invention relates to a flame-monitoring device in which an a.c. input voltage (U1) is limited to a voltage limit (U2) by means of a voltage limiter (4). Said voltage limit (U2) is applied to a flame sensing device (7) which operates by means of the rectifying effect of a flame, and through which a current (i) flows, especially when a flame (6) is present. An asymmetric voltage limit (U2) can be defined by said voltage limiter (4), said limit being then applied to the sensing device (7).
