1. A device for controlling a person's authorization upon utilization of a service with a data carrier that communicates with a reader, and with a sensor for detecting the person's biometric identification features, a memory for the authorized person's biometric identification features and means for comparing the stored biometric identification features with those detected, characterized in that the data carrier is formed by an object ( 1 ) worn on the skin and communicates contactlessly with the reader ( 4 ), and the sensor ( 3 ) is disposed on the side of the object ( 1 ) facing the skin and is formed for detecting biometric identification features of the skin located thereunder.