A magnetoresistive sensor element is provided, having a magnetoresistive
layer system which, in top view, is at least regionally striated. The
sensor element operates on the basis of the GMR effect and is constructed
according to the spin valve principle, the striated layer system
featuring a reference layer having a direction of magnetization
substantially uninfluenced by a direction of an outer magnetic field
acting on it. During operation, the sensor element provides a measuring
signal which changes as a function of a measurement angle between the
component of the field strength of the outer magnetic field lying in the
plane of the layer system, and the direction of magnetization, and from
which this measurement angle is able to be ascertained. In addition,
observed in a top view of the striated layer system, the angle between
the direction of magnetization in the absence of the outer magnetic field
and the longitudinal direction of the striated layer system is set in
such a way that in response to an influence of the outer magnetic field
having a defined field strength, which is selected from a predefined work
interval, the angle error of the layer system, as a function of this
angle and the field strength, is minimal.