A control apparatus capable of updating a user program while processing is being performed in a multitasking manner is provided. A processor includes a memory that stores a user program containing a program organization unit as well as a central processing unit executing a task containing the user program and also updating the program organization unit stored in the memory. The central processing unit is configured to execute a plurality of tasks concurrently and to execute each task with a period corresponding to the task. Moreover, the central processing unit is configured to update the program organization unit stored in the memory during the period of time from when a plurality of tasks to be executed have been finished until when the plurality of tasks are executed again.