A device for detecting a manipulation to a program code wherein the program code is configured to be executed from an execution environment on a computing system, is provided. The device includes a comparator unit which is configured to compare data of the program code with reference data in order to produce a comparison result to compare, if the execution environment conveys a termination command to the program code, and a detection unit which is configured to detect a manipulation of the program code on the basis of the comparison result. The device can prevent data, which is produced or used during the execution of a program code, from continuing to be used after termination of the program code if an attack or manipulation of the program code has occurred. A method is further proposed for detecting a manipulation to a program code.