NOVELTY - The current sensor has a magnetoresistance effect element (12a,12b) in which magnetic detecting portions (32) and permanent magnet portions (33) are alternately arranged so as to contact each other. Each magnetic detecting portion has a ferromagnetic fixed layer whose magnetization direction is fixed and a free magnetic layer whose magnetization direction changes in accordance with external magnetic field. Each permanent magnet portion has a hard bias layer for applying a bias magnetic field to free magnetic layer. The interval between adjacent permanent magnet portions is 20-100 micrometers.    USE - Current sensor for detecting magnitude of current for driving motor of e.g. electric vehicle, solar cell.    ADVANTAGE - Provides current sensor having low magnetic hysteresis, high linearity, and high detection sensitivity since interval between adjacent permanent magnet portions is set to 20-100 micrometers. The insensible region of free magnetic layer is sufficiently decreased since area of contact portion between the free magnetic layer and hard bias layer is not increased by providing each permanent magnet portion between adjacent magnetic detecting portions in magnetoresistance effect element. Obtains current sensor in which low magnetic hysteresis, high linearity, and high detection sensitivity are well balanced since width of each magnetic detecting portion is preferably 0.5-1.5 micrometer. Current sensor with high measurement accuracy is obtained since adjacent magnetic detecting portions are electrically connected to each other by the electrically conductive layer so that increase, variation, or the like of electric resistance by each permanent magnet portion is suppressed. The characteristics of current sensor are remarkably enhanced since characteristics of the magnetoresistance effect element are directly linked to the characteristics of current sensor.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic plan view of the magnetoresistance effect element used in a current sensor.    Magnetoresistance effect elements (12a,12b)    Elongated pattern (31)    Magnetic detecting portion (32)    Permanent magnet portion (33)    Connection terminals (34a,34b)