A magnetic storage device includes first and second magnetic layers and a non-magnetic layer, where the non-magnetic layer includes a first oxide layer containing magnesium and oxygen, a second oxide layer containing magnesium and oxygen, a third oxide layer containing zinc and oxygen, a fourth oxide layer containing a first predetermined element and oxygen, and a fifth oxide layer containing a second predetermined element and oxygen, and a crystal structure of an oxide of the first predetermined element and a crystal structure of an oxide of the second predetermined element are each a rock salt structure. The first predetermined element and the second predetermined element each have an oxide formation free energy greater than an oxide formation free energy of zinc, and the oxide of the first predetermined element and the oxide of the second predetermined element each have a bandgap narrower than a bandgap of an oxide of magnesium.