Method and apparatus for erasing memory data

A memory erasing method and apparatus for erasing important data of a nonvolatile memory within the apparatus to prevent illegal access using attitude information measured in an inertial measurement sensor and a low power microprocessor regardless of the power supply state of the apparatus. The apparatus includes a power switching circuit unit for selecting one from among an external power source and a battery. An inertial measurement sensor measures attitude information of the memory erasing apparatus, using power supplied from the external power source or the battery. A low power microprocessor erases important data from a memory device in a first manner using power from the external power source, and in a second manner using power from the battery, the first manner being different from the second manner.