To quickly attenuate vibrations of a load cell by a compact and simple apparatus when a weight is measured, and enable high-speed highly accurate measurements, by providing the load cell which detects the weight from a shift of a movable part and outputs a weight signal, and a magnetic damper having a cylindrical member of good conductivity and a magnetic circuit generating a magnetic flux.

When an object M to be measured is placed on a measurement saucer 5a, a strain gauge 2 incorporated in a bridge circuit 3 detects a distortion amount corresponding to a change of a movable part 1c of a load cell 1 and outputs a weight signal. The weight signal includes a vibration component consequent to an up-down movement of the cell 1 in addition to a weight of the object M to be measured. A brake force (attenuation force) of a magnetic damper 9 is proportional to a relative moving speed of a cylindrical member 6 and a square of an interlinking magnetic density and, inversely proportional to a resistivity of the member 6. Therefore, the magnetic damper is constituted of a member having a small resistance in a circumferential direction, a permanent magnet 8b is formed of an anisotropic sintered magnet of large coercive force, and a yoke main body 8a and a center yoke 8c are formed of ferromagnetic material of large magnetic permeability, thereby making the apparatus compact and capable of performing high-speed calculations.