Abstract: A magnetic sensor device comprising a magnetic element and a wire wound around the magnetic element. The magnetic element has a cross-sectional area of not more than 0.55 mm.sup.2 and a saturation magnetostriction constant .lambda.s whose absolute value is smaller than 1.times.10.sup.-6, with Sw/Sm being equal to or smaller than 9, provided that Sw is the cross-sectional area of the wire and Sm is the cross-sectional area of the magnetic element. Preferably, the magnetic element has an elastic limit .sigma.m greater than 1,000 MPa, and the elongation the magnetic element experiences upon application of a stress equal to the elastic limit .sigma.m is between 1.0% and 5.0%. It is also preferable that the magnetic element and the wire are covered with a resin layer to form an integral unit.