A insertion electrode device, which is configured for installing a sensor probe in a container for a measuring medium, includes a probe housing that can be attached to the container and has a probe protector tube serving to receive, hold and guide the sensor probe. The sensor probe has a coupling for electrical connections, and the probe housing is equipped with a protective sleeve to protect the coupling from mechanical stress and moisture. The protective sleeve is connectable to the probe protector tube. A safety adapter is coupled to the end of the probe protector tube that is outside the container. The safety adapter engages a recess of the sensor probe or reaches over a step of the sensor probe and thereby secures the latter against moving in the axial direction.