The present invention provides a magnetoresistance effect element that has a first ferromagnetic metal layer, a second ferromagnetic metal layer, and a tunnel barrier layer provided between the first ferromagnetic metal layer and the second ferromagnetic metal layer. The tunnel barrier layer has a cubic crystal structure, and the first ferromagnetic metal layer or the second ferromagnetic metal layer is formed of a material having a cubic crystal structure represented by Fe2CoSi. A crystal surface for crystals constituting the tunnel barrier layer and a crystal surface for crystals constituting the first ferromagnetic metal layer or the second ferromagnetic metal layer are matched to be inclined at 0° or 45° in at least a part of a crystal interface between the tunnel barrier layer and the first ferromagnetic metal layer or the second ferromagnetic metal layer.