A portable radio receiver with an automatic power generator has a ring-shaped receiver body, a coil, a magnetic material, a rechargeable battery and a receiver unit. The coil is wound in proximity to the receiver body. The magnetic material is movably located inside the coil. The rechargeable battery is provided for accumulating electric charge which is generated on the coil as the magnetic material moves. The receiver unit utilizes the rechargeable battery as a power source.