The present invention relates to a magnetic tunnel junction device and a manufacturing method thereof. The magnetic tunnel junction device includes: i) a first magnetic layer including a compound having a chemical formula of (A100-xBx)100-yCy; ii) an insulating layer deposited on the first magnetic layer; and iii) a second magnetic layer deposited on the insulating layer and including a compound having a chemical formula of (A100-xBx)100-yCy. The first and second magnetic layers have perpendicular magnetic anisotropy, A and B are respectively metal elements, and C is at least one amorphizing element selected from a group consisting of boron (B), carbon (C), tantalum (Ta), and hafnium (Hf).