An adjusting device is for a thermal trip element of a switchgear. It includes a bimetallic element that is stationarily fixed on a bimetallic support. The free end of the bimetallic element is spaced apart form a trip lever and increasingly impinges the same in the direction of release was a result of the thermal deformation, the distance being adjustable by bending the bimetallic support. The adjusting device is especially suitable for circuit breakers or the like.