A current amplifying element that operates at a higher speed than conventional semiconductor devices is provided. An input current flows through an input current path 60 in a direction X, and a magnetic field generated from a magnet 90 is applied in a direction Z which is perpendicular to the direction X. An output current path 70 is formed under the input current path 60 with an insulator 80 interposed therebetween. Since the direction in which an output current flows is perpendicular to both the input current and the magnetic field, the current is amplified by the galvanomagnetic effects produced by the input current and the magnetic field.