Abstract
A very thin Al film (thickness: 160–430 Å) was evaporated on a silicon wafer substrate with a SiO2 film and an arachidic acid Langmuir-Blodgett film. Vanishing of resistance and a repulsive force indicating diamagnetism were observed in the very thin Al film in a magnetic field at room temperature. This repulsive force was measured by an apparatus which can measure small displacements such as 10-2 µm with a laser beam.