According to some embodiments, an aerosol generating device may include a battery, a first control circuit configured to convert power received from the battery into a pulse width modulation (PWM) signal, a heater configured to heat an aerosol generating article based on the PWM signal received from the first control circuit, and a second control circuit configured to transmit an instruction for causing the first control circuit to generate the PWM signal, in response to a user input to the first control circuit. The first control circuit may determine abnormal operation of the second control circuit, and the second control circuit may determine abnormal operation of the aerosol generating device. Accordingly, the aerosol generating device may determine a more specific operation state and prevent abnormal operation of the heater.