A biometric apparatus includes a first detector that detects and outputs a brain activity signal indicating a state of brain activity in a target person, and a signal processing circuit. The signal processing circuit acquires the brain activity signal, acquires a biological signal of the target person that is different from the brain activity signal, determines, based on the biological signal and the brain activity signal, whether a state of the target person is an awake state, a sleeping state, or an unconscious state, and generates and outputs a signal indicating the state of the target person.
