Abstract: The object detection sensor includes: a sensing unit to detect to-be-detected rays from a target object to output a sensing signal, a control unit to command output of a predetermined detection signal in response to input of sensing signal, a sensor output to output predetermined detection signal in response to command, a test signal reception to receive a test signal, and a test signal response to output a test response signal in response to reception of test signal, and further includes: a learning mode transition input to start a learning mode, a test signal determination to determine a state of received test signal in learning mode, a test signal estimation to estimate a characteristic of test signal from determined state of test signal, and a test signal verification to verify whether estimated characteristic of test signal is included in test signal received by test signal reception.