An electromagnetic pointer is disclosed. The electromagnetic pointer comprises a pen holder assembly, a circuit board, a metal rod, a ferrite core with coils and a trigger device. The diameter of the pen holder assembly is less than 6 mm. The circuit board comprises a resonance circuit. The metal rod has a low permeability. The ferrite core with coil constitutes an inductor and the coil electrically connects to the circuit board through a conductive wire to complete the resonance circuit. The ferrite core has a hollow center so that the metal rod can move through to trigger the trigger device and change electric properties of the resonance circuit.