Magnetic sensing element having no variation in track width and capable of properly complying with track narrowing

A magnetic sensing element comprising a magnetoresistive film having a portion exhibiting magnetoresistance, and bias layers and electrode layers provided on both sides of the magnetoresistive film in a track width direction;

• wherein the electrode layers are formed to extend from the rear in a height direction to the magnetoresistive film;
• the bias layers are disposed on both sides of the magnetoresistive film in the track width direction,
• the electrode layers have a predetermined space therebetween in the track width direction over the magnetoresistive film,
• the electrode layers are formed over the bias layers,
• the bias layers are not disposed below inner side end faces of the electrode layers which are formed behind the magnetoresistive film in the height direction and a distance between the inner side end faces of the electrode layers increases towards the rear in the height direction;
• peripheries of the magnetoresistive film and the bias layers, except a surface facing a recording medium, are filled with an insulating layer so that the inner side end faces of the electrode layers are formed on the insulating layer, and
• an upper surface of the magnetoresistive film is coplanar with upper surfaces of the bias layers and the insulating layer.