PURPOSE: To record and reproduce a short wavelength signal by setting the gap length direction of a magnetic head to the same direction as a moving direction of a magnetic recording medium or a magnetic head, and varying a width of opposed cores for constituting a gap of the magnetic head.

CONSTITUTION: Tape head system is constituted of a magnetic head 1, a magnetic tape 2 and a magnetic head supporting body 4, and the head 1 is moved against the direction as indicated with an arrow. A gap part G1 is formed by an opposed core 6 and 7. A width of the core 6, a width of the core 7, and a gap width are denoted as N, M and GA, respectively. As for the tape 2, a track 8 is formed by a magnetizing vector 9 shown by many arrows. The core width M of one side is set to ≤1/2 of a recorded signal wavelength. In this way, a short wavelength recording signal can be reproduced. Also, short wavelength recording of the same extent as vertical magnetization can be executed. Moreover, the magnetic head can be installed to only one side of a recording medium.