According to an embodiment, a magnetic tunnel junction includes a tunnel barrier layer provided between a first magnetic layer and a second magnetic layer. The tunnel barrier layer is a crystal body made of a stacked structure of a first insulating layer and a second insulating layer. The crystal body is oriented. The first insulating layer is made of an oxide of Mg1-xXx (0≤x≤0.15). X includes at least one element selected from the group consisting of Al and Ti. The second insulating layer is made of an oxide of an alloy including at least two elements selected from the group consisting of Mg, Al, Zn, and Li. Both the first magnetic layer and the second magnetic layer are made of an alloy including B and at least one element selected from the group consisting of Co and Fe.