A perpendicular magnetic recording head capable of preventing information erasing without intention at the time of non-recording through making the magnetic domain structure of a pole layer appropriate is provided. A main pole layer is formed so as to include a first pole layer portion having a first width W1 which determines the recording track width of a recording medium and a length L1, a second pole layer portion having a width which gradually expands from the first width W1 to a second width W2 larger than the first width W1 (W2>W1) and a length L2, and a third pole layer portion having a third width W3 larger than the second width W2 (W3>W2) and a length L3. When the ratio W3/(L1+L2+L3) satisfies a relationship of W3/(L1+L2+L3).gtoreq.1.0, on the basis of the shape magnetic anisotropy of the main pole layer, the magnetic domain structure of the main pole layer is made appropriate so that an unnecessary magnetic flux is not easily leaked at the time of non-recording.