The present invention provides a fluxgate magnetic sensor element which includes: a substrate; an exciting pattern which is disposed on the substrate to generate a magnetic field; a magnetic thin film pattern for detection which is disposed adjacent to the exciting pattern; and a detection coil pattern which is disposed adjacent to the magnetic thin film pattern for detection. In the magnetic sensor element, the exciting pattern, the magnetic thin film pattern for detection, and the detection coil pattern are formed on the substrate. Therefore, the magnetic sensor element can be formed into a flat shape. Moreover, since the length of the generated magnetic field is short in a long-axis direction, the size and thickness of the element itself can be reduced.