The invention is directed to an apparatus for continuous and non-destructive monitoring of the connection of a conveyor belt. During movement of the conveyor belt, a radiation source emits rays in the direction of the belt surface. The rays are of such high energy that they penetrate the conveyor belt and the connection thereof within a material-free region. A sensor detects the rays which have passed through. A process computer evaluates the result of the radiographic examination by comparing the actual connection values to set connection values and connection limit values. The radiation source and the sensor are accommodated in a housing. The housing has two openings between the radiation source and the sensor through which the moving conveyor belt passes without contact. The housing is integrated into the lower run of a conveyor system.