in a multitask execution environment , a debugging device performs debugging setting for rewriting part of original recording content in a memory area shared by at least two tasks , and debugging cancellation for restoring rewritten recording content back to original recording content . the debugging device stores a memory area used by each task , and address information specifying each debugging target task and a respective address . when task switching occurs , if a next task is not a debugging target , recording content at a physical address specified by address information other than that of the next task and within the physical address space range used by the next task is put into a post - debugging cancellation state . if the next task is a debugging target task , in addition to the above processing , recording content at the physical address specified by the address information of the next task is put into a post - debugging setting state .