Abstract: A magnetic recording and reproducing device comprises a tape guide mechanism for taking up the tape within the cassette when unloaded state, and withdrawing the tape from the cassette so as to wind the tape on the rotary head drum when loaded state. The mechanism comprises a first guide slot, a first moving member, and a first guide roller provided on the first moving member. The center line of the tape wound on the first guide roller lies in the reference plane. The mechanism comprises a second guide slot provided on take-up reel side and having a slanting part, a second moving member, and a second guide roller provided on the second moving member. The second guide roller rotates about a second axis having a predetermined tilt angle and a predetermined direction angle so that the center line of the tape is situated lower than the reference plane, is wound from the rotary head drum so that the center line of the tape is oriented toward the reference plane.