A plurality of gap patterns are formed on a front surface of a substrate along a direction corresponding to a width direction of a magnetic tape. The first straight line region has a steeper inclined angle with respect to the first imaginary straight line than the second straight line region. Positions of both ends of the first straight line region and positions of both ends of the second straight line region are aligned in a direction corresponding to a width direction of a magnetic tape. Positions of the plurality of gap patterns are aligned in a longitudinal direction of the magnetic tape. A pulse signal is supplied to each of the plurality of gap patterns with a delay of a predetermined time from one side to the other side in a direction in which the plurality of gap patterns are arranged.