A magnetic RAM using a thermo-magnetic spontaneous hall effect, and a data writing and reading method using the magnetic RAM are provided. The magnetic RAM includes a MOS transistor, a memory layer, a heating means, and a write line. The memory layer is connected to the source of the MOS transistor and writes data to itself. The heating means heats the memory layer. The write line applies a magnetic field to the memory layer in order to change the magnetization state of the heated memory layer. The magnetic RAM can increase the coercivity caused by highly-integration and improves the thermal security of a cell. The MRAM can operate at an ultra speed because of a small cell resistance. In addition, since the magnetic RAM can be simply manufactured by an existing semiconductor manufacturing process, the manufacturing costs are reduced. Furthermore, since the magnetic RAM writes or reads data using the fact that a spontaneous hall voltage greatly differs according to the magneticization state of a memory layer, it provides a high data sensing margin.