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.