A control apparatus for controlling a control object, comprising: a processor; a first program which is repeatedly executed by the processor and has a highest execution priority; a second program having a lower execution priority than the first program; a third program having a lower execution priority than the second program; and a scheduler program which manages programs executed by the processor, wherein the second program includes a notification command for outputting a start notification according to start of execution in the processor and outputting an end notification according to completion of execution in the processor, and the scheduler program includes a command for causing the processor to execute the second and third programs such that execution of the first program is not obstructed, and a command for determining an execution state of the second program in each predetermined monitoring cycle on the basis of the start notification and the end notification from the second program; characterized by a fourth program having a higher execution priority than the second program, wherein the scheduler program includes a command for temporarily interrupting execution of the fourth program when the execution state of the second program does not satisfy predetermined settings, the command for determining the execution state includes a command for determining an execution state of the third program in the monitoring cycle, and the scheduler program includes a command for temporarily interrupting execution of the second program when the execution state of the third program does not satisfy predetermined settings. a processor; a first program which is repeatedly executed by the processor and has a highest execution priority; a second program having a lower execution priority than the first program; a third program having a lower execution priority than the second program; and a scheduler program which manages programs executed by the processor, wherein the second program includes a notification command for outputting a start notification according to start of execution in the processor and outputting an end notification according to completion of execution in the processor, and the scheduler program includes a command for causing the processor to execute the second and third programs such that execution of the first program is not obstructed, and a command for determining an execution state of the second program in each predetermined monitoring cycle on the basis of the start notification and the end notification from the second program; characterized by a fourth program having a higher execution priority than the second program, wherein the scheduler program includes a command for temporarily interrupting execution of the fourth program when the execution state of the second program does not satisfy predetermined settings, the command for determining the execution state includes a command for determining an execution state of the third program in the monitoring cycle, and the scheduler program includes a command for temporarily interrupting execution of the second program when the execution state of the third program does not satisfy predetermined settings.