An electromagnetic forming device for a sheet of material is provided. The electromagnetic forming device includes a fixing base, a magnetic concentration block, an electromagnetic actuator, and a die. The fixing base has a groove. The magnetic concentration block is disposed in the groove of the fixing base, and has an accommodating space therein, which is in communication with a surface of the magnetic concentration block via a slit. The electromagnetic actuator, used to generate a magnetic field, is disposed in the accommodating space of the magnetic concentration block, but does not contact the magnetic concentration block. The die and the magnetic concentration block are separated by a gap, and a sheet of material can be disposed in the gap. As the magnetic concentration block is a block, eddy currents in the magnetic concentration block are distributed uniformly, so the generated magnetic field is also distributed uniformly, thus exerting a uniform forming force on the sheet of material.