To detect both an acceleration and an inclination with good accuracy by using one sensor, by a method wherein the movement direction of a permanent magnet is regulated to one direction by using a leaf spring.

A support base 5 is attached to the frame of an object to be detected such as a motorized bicycle, a motorized wheelchair or the like, in such a way that a leaf spring 6 becomes vertical. When the object to be detected is tilted forward or backward by an angle θ, also the support base 5 is tilted, the leaf spring 6 is deformed, and the position of a permanent magnet 9 is displaced with reference to a magnetoresistance element 11. It is assumed that, when the object to be detected is in a horizontal state, a constant output is generated. Then, an output voltage is decreased when the permanent magnet 9 is displaced to the front direction as shown in Fig. 2b, and when the permanent magnet 9 is displaced to the rear directions shown in Fig. 2c, the output voltage is increased. When an acceleration exists in the movement direction of the object to be detected, the permanent magnet 9 is moved to a direction opposite to a direction in which the acceleration acts. As a result, the acceleration can be detected in the same manner as a case in which the object to be detected is tilted.