To provide a program tracing device with which when which task processing or interruption processing destroys a queue is immediately recognized.

When going through the interruption processing or at the beginning of the task switching processing of a real time monitor, by checking whether or not the interruption processing or the task processing in a RUN state immediately before accesses resources in a possible range, the error of the way of using the resources of a memory and a timer, etc., is detected by the performance of only the task processing and the interruption processing.