A magnetic recording/reproducing apparatus is provided in which among diametrically oppositely disposed heads, a recording head and an erasing head of a same channel are disposed adjacently to each other. The recording head is disposed so as to precede by two tracks the erasing head with respect to a direction of cylinder rotation, when insert-editing, using a reproduced signal obtained by the recording head, erase and record timing setting and head tracking are performed and an erasing current is not applied during the reproduction by the recording head. The reproducing heads are disposed so as to be angularly apart by about 90 degrees from the recording and erasing heads, and a rotary transformer for reproduction is applied with a shield measure and then, formed as a core independently at an upper portion of the cylinder. In addition, more narrow tracks are compatibly reproduced by the recording head.