A magnetism-erasing circuit for use in cathode ray tubes of portable televisions or the like for erasing the magnetism from the cathode ray tubes is disclosed. The magnetism-erasing circuit includes: a) automatic trigger for an automatically generating trigger signals when a D-C supply is initially applied to the magnetism-erasing circuit, b) trigger detecting means, c) delay and second trigger means for generating second trigger pulses which are delayed by a specified time interval by the detected trigger signals from the trigger detecting means, and d) means for controlling the driving of the magnetism-coil by applying currents to a magnetism-erasing coil. The magnetism-erasing circuit of the present invention further includes manual trigger means for manually generating trigger signals under the condition where a D-C supply has already been applied to the circuit.