<p>Disclosed is a driving behavior detecting method in which driving behavior is detected on the basis of acceleration of a vehicle (A) detected by an acceleration sensor (2) using a driving behavior detecting unit (3) installed in the vehicle (A) and having at least the acceleration sensor (2). An inclined state detecting means (11) automatically detects the state of the inclination angle of the anteroposterior axis of the installed driving behavior detecting unit (3) with respect to at least the anteroposterior axis of the vehicle (A) on the basis of frequency of occurrence of the acceleration detected by the acceleration sensor (2) in a predetermined travelling state at a plurality of inclination angles on a plane including a predetermined axis of the vehicle (A) and a predetermined axis of the driving behavior detecting unit (3) obliquely disposed with respect to the predetermined axis of the vehicle (A).</p>
