PURPOSE: To easily obtain the magnitude of a load by measuring an inductance by applying the load to a load connecting member, producing a distortion in a sensing member, changing its permeability and accordingly changing the inductance of a detecting coil.

CONSTITUTION: A rectangular sensing member 1 is fixed at both ends to an annular base material 2 and a load connecting member 3 is fixed to the central portion of the member 1. The members 1 and 3 are stuck to each other by caulking with rivets 3a. The member 1 is the sheets of the spring material made up of the ribbon 1a of an iron amorphous alloy with excellent magnetostrictive characteristics and phosphor bronze. The ribbon 1a is plated with a thin copper to both surfaces in advance and integrally adhered to spring members 1b and 1c by a polymerizable macromolecular adhesive 1d. When a load is applied to the member 3 of a force sensor, a distortion is produced in the member 1 and its permeability is changed to change the inductance 24 of detecting coils 4. Thus, by measuring the inductance 24, the magnitude of the load can be learned.