The magnetic memory element (100) includes: a conductive layer that includes a heavy metal layer (10) containing a 5d transition metal; a first ferromagnetic layer (20) that is adjacent to the conductive layer and contains a ferromagnetic layer having a reversible magnetization; a barrier layer (30) that is adjacent to the first ferromagnetic layer (20) and includes an insulating material; a reference layer (40) that is adjacent to the barrier layer (30) and has at least one second ferromagnetic layer (41) having a fixed magnetization direction; a cap layer (50) that is adjacent to the reference layer (40) and includes a conductive material; a first terminal (T1) that is capable of introducing a current into one end of the heavy metal layer (10) in the longitudinal direction; a second terminal (T2) that is capable of introducing a current into the other end of the heavy metal layer (10) in the longitudinal direction; and a third terminal (T3) that is capable of introducing a current into the cap layer (50).