Embodiments in accordance with the present invention provide a perpendicular recording magnetic head whose dimensional dependency on the nonuniformity of magnetic field strength and distribution during manufacture is minimized, with narrowed tracks and without attenuation or erasure of adjacent track data while maintaining high magnetic field strength. According to one embodiment, a magnetic material (trailing/side shield) for creating a steep gradient of magnetic field strength is provided at a trailing side of a pole tip of a main magnetic pole piece and in a direction of the track width. The magnetic head is formed so that a gap (side gap length “gl”) between a side shield and a throat height portion of the pole tip progressively decreases with an increasing distance from an air-bearing surface, in a direction of an element height. That is, side gap length “gl” (2) at an element height position P2 is made smaller than side gap length “gl” (1) at an air-bearing surface position P1 so as to satisfy a relationship of gl(1)>gl(2).