To provide a magneto-resistive(MR) element which can be enhanced in heat radiation efficiency and a thin-film magnetic head as well as a process for producing the same.

The MR element includes a laminate 5 formed by laminating a free layer 54 which is a magnetic layer changing freely in a magnetization direction, a magnetic separation layer 53 consisting of a nonmagnetic metal, a bid layer 52 which is a magnetic layer fixed in the magnetization direction to one direction and an antiferromagnetic material layer 15 for fixing the magnetization direction of this bid layer 52. A tapered surface 5A inclined with respect to a medium-facing surface S is formed on the end face of the laminate 5 on the side opposite to the medium-facing surface S. The element is so constituted that the distance to the surface opposite to the medium-facing surface S of the antiferromagnetic material layer 51 is greater than the distance to the surface opposite to the medium-facing surface S of the free layer 54. As a result, a sufficient heat radiation quantity from the antiferromagnetic material layer 51 may be assured and the heating of the MR element may be suppressed.