A magnetic sensing element using a thin film composed of an adequately crystallized Heusler alloy is provided. At least one of free magnetic layer and pinned magnetic layer includes a Heusler alloy layer. The Heusler alloy layer has a body-centered cubic (bcc) structure, in which equivalent crystal planes represented as [220] planes are preferentially oriented in the direction parallel to the layer surface. The Heusler alloy layer is disposed on a bcc layer having a body-centered cubic (bcc) structure, in which equivalent crystal planes represented as [110] planes are preferentially oriented in the direction parallel to the layer surface.