A random number generator using a stochastic magnetic tunneling junction structure is proposed. The random number generator includes: a first magnetic tunneling junction structure including a first pinned layer, a first tunnel junction layer, and a first free layer that are sequentially stacked, and stochastically having a parallel state and an anti-parallel state in which a magnetization direction of the first pinned layer and a magnetization direction of the first free layer is parallel and anti-parallel, respectively; and a first power supplier connected to the first magnetic tunneling junction structure and configured to supply AC voltage/current to the first magnetic tunneling junction structure.