The present invention achieves high speed safe response performance. A safety controller (100) includes a first voltage monitoring circuit (12) and a second voltage monitoring circuit (22). The first voltage monitoring circuit (12) is an AD converter which operates upon receiving electric power from a second electric power source (21) and which transmits, to a second MPU (20), a signal that gives notification of occurrence of an anomaly in a first voltage value. The second voltage monitoring circuit (22) is an AD converter which operates upon receiving electric power from a first electric power source (11) and which transmits, to a first MPU (10), a signal that gives notification of occurrence of an anomaly in a second voltage value.