The present invention provides a thin film magnetic head achieving improved recording performance by sharpening recording magnetic field gradient as much as possible. The thin film magnetic head has a return yoke layer disposed on a trailing side of a magnetic pole layer, and width W3 of an exposed surface of a lower TH specifying part in a TH specifying portion in the return yoke layer is equal to or larger than width W1 of an exposed surface of the magnetic pole layer (W3.quadrature.W1), and is less than width W4 of an exposed surface of an upper TH specifying part (W3