Abstract: A single-electron controlling magnetoresistance element which comprises, a couple of first ferromagnetic bodies each magnetized in a first direction, a second ferromagnetic body magnetized in a second direction in an initial direction and sandwiched between the couple of first ferromagnetic bodies with a tunnel junction interposed therebetween respectively, and means for directing the magnetization direction of the second ferromagnetic body to a direction different from the second direction, wherein a charging energy E.sub.c of a single electron in at least one of the tunnel junctions interposed between the first ferromagnetic body and the second ferromagnetic body meets the following conditions:E.sub.c >>k.sub.B T (2)E.sub.c >>h/R.sub.t C (3)wherein k.sub.B T is a thermal energy at an operation temperature, h is a Planck's constant, R.sub.t is a junction tunnel resistance, and C is a junction capacity.