Rotation angle sensor capable of accurately detecting rotation angle

A rotation angle sensor comprising:

• a fixed part on which giant magnetoresistive elements are provided, each of the giant magnetoresistive elements having a multilayer body including a fixed magnetic layer with a fixed direction of magnetization, a non-magnetic conductive layer, and a free magnetic layer facing said fixed magnetic layer with said non-magnetic conductive layer held between them, and electrode layers connected both ends of said multilayer body;
• and a rotating part which forms a magnetic field and rotates facing said fixed part,
• wherein said giant magnetoresistive elements with their fixed magnetic layers having opposite directions of magnetization are provided as a pair on a surface of said fixed part, and said giant magnetoresistive elements as a pair are connected so that a difference between their resistance values is outputted, thus detecting a magnetic field component parallel to the surface of said fixed part provided from said rotating part to said giant magnetoresistive elements,
• wherein the size of said multilayer body of said giant magnetoresistive element is 1 mm or smaller, and when the shape anisotropy energy (H) of said free magnetic layer is expressed by H=A*Js*(Br/π), where Js represents saturation magnetization of a magnetic material forming said free magnetic layer and Br represents remanent magnetic flux density of the magnetic material forming said free magnetic layer, −350<A<0 holds.