To provide a magneto-resistance effect head wherein heat generation is suppressed even when the current density of a sense current is high on a magneto-resistance effect film, and an information reproducing device provided with such a magneto-resistance effect head regarding the magneto-resistance effect head for reproducing information from a magnetic recording medium by detecting the resistance change of a magneto-resistance effect film exhibiting the resistance change in accordance with the direction of magnetization, and the information reproducing device for reproducing information from the magnetic recording medium by detecting the resistance change.

The height dimension of the center of a magneto-resistance effect film is shorter than an end, or the magneto-resistance effect film has an end varied in width in accordance with the position in a height direction.