In manufacturing the thin film magnetic head, the rear end face of the MR element and the rear end face of a resistive film pattern are determined with high precision using a mask pattern, in which a first opening and a second opening are collectively formed. The first and second openings are located side by side in a track-width direction. The first opening includes a first edge extending across the MR film in the track-width direction, and the second opening includes a second edge located at a given interval, as measured in a direction orthogonal to the track-width direction, from the first edge, and extending in the track-width direction. In the step of polishing for forming a magnetic-recording-medium-facing-surface, the amount of polishing is determined by monitoring the resistance change of the resistive film pattern, thereby reducing the dimension errors in the MR height when manufacturing the MR element.