<p>A tension sensor for sensing tension in the magnetic tape by measuring variations in an inductance value which arise as a result of applying stress which has been transformed from tension in the object to be measured to an amorphous magnetic alloy part of an inductance element. The magnetostrictive effect of the amorphous magnetic alloy which is both resilient and magnetostrictive is utilized in sensing the tension in the tape. The magnetic alloy is used for at least a part of a magnetic core of the inductance element.</p>