PURPOSE: To produce at a high speed a reciprocating recording/reproducing type recorded magnetic tape by using two rotary heads consisting of N units of element heads with different azimuth angles to carry out recording on a magnetic tape which is driven at a speed NV which is N times as high as the speed V of a prescribed tape.

CONSTITUTION: Two rotary heads Ha and Hb are set at symmetrical positions by 180° in the circumferential direction of a head cylinder HS and in the direction of a prescribed angle (-θ and +θ). Both heads form simultaneously N pieces of parallel recording tracks by N units of element heads at the 1st and 2nd areas Dg and Dc set between a record starting position near a side edge (a) of a magnetic tape T which is driven at a speed NV which is N times as high as the speed in a reproduction mode and the record ending position near the other side edge (b) of the tape. In this case, both heads form the recording tracks alternately and according to the revolution of the cylinder HS. Thus it is possible to produce at a high speed a recorded tape for rotary head type recording/reproducing device.