Patent ID: 7403352

Claim:
An acceleration sensor comprising: a housing member; a spring member attached to said housing member, said spring member having freedom in at least one direction of acceleration to be detected; a magnetic field generation member fixed to said housing member; and at least one magnetic field detection sensor and a weight member, fixed to said spring member so that said at least one magnetic field detection sensor faces said magnetic field generation member, said at least one magnetic field detection sensor provided with at least one multi-layered magnetoresistive effect element including a magnetization fixed layer and a magnetization free layer, a magnetic field being applied to said at least one multi-layered magnetoresistive effect element from said magnetic field generation member in a direction substantially perpendicular to a lamination plane of said at least one multi-layered magnetoresistive effect element when no acceleration is applied, and, when an acceleration is applied, the magnetic field being applied to said at least one multi-layered magnetoresistive effect element from said magnetic field generation member in a direction changed by an angle corresponding to the applied acceleration from said substantially perpendicular direction.