PURPOSE: To achieve a standardization of a magnetoresistive element while expanding freedom in the assembling of the element by making the magnetoresistive element with one resistance part as one chip part to be carried on a substrate arranged in a pattern for a purpose generated separately.

CONSTITUTION: A magnetoresistive element chip 1 is carried on a substrate 2 on which a pattern is formed at an element pitch determined to match the shape of a magnetic flux density varying part to be combined. As a result, when the shape of the magnetic flux varying part to be combined is altered, the magnetoresistive element can be changed to the optimum layout simply by altering the pattern of the substrate 2. For example, a magnetoresistive element assembly formed by the magnetoresistive element chip 1 and the substrate 2 so as to face a gear 10 is arranged and a bias magnet 3 is arranged behind the assembly. With the rotation of the gear 10, a flux density applied to the magnetoresistive element 1 varies to change the resistance value of the element 1 and the varying of a magnetic flux is converted to an electrical signal to detect an angle of rotation.