PURPOSE: To increase the number of tracks per tape by realizing a both sides magnetic tape in order to increase the recording density of a magnetic tape device, and also, to provide a both sides magnetic tape device having high density and a high transmission speed.

CONSTITUTION: The both sides magnetic tape device is provided with many magnetic heads 101 of a fixed form having a fixed position with respect to a plane of a magnetic tape attached in the inside of a both sides magnetic tape, and a slider head 109 which is connected to a supporting mechanism opposite to the magnetic head concerned and attached to the outside of the both sides magnetic tape. Also, in order to maintain the operation state of the magnetic heads no both sides to the both sides magnetic tape, a means for pressing the outside slider head 109 toward many inside magnetic heads 101 of the fixed form is provided so that the magnetic head is operated to both side faces of the both sides magnetic tape.