Abstract: The invention relates to a method for operating a chip card (C), a microprocessor for being inserted into the chip card (C) and a computer program product, as well as a method for manufacturing and/or for maintaining a chip card (C) which is operated with the help of a method described above. Here central multi-tasking kernel (MTK) is provided, which controls the entire operation of the chip card (C), so that there can be activated a plurality of application programs (A) on the chip card (C) at the same time, an application program (A) also being able to realize security technical functions for the chip card (C).