PURPOSE: To simplify the constitution of a cassette magnetic recorder and reproducer by allowing a cassette supporting member to operate as a moving means for a cassette and also as a holding means for a cassette positioned at a recording and playback position.

CONSTITUTION: The 1st bottomless cassette supporting member 1 has a loading and unloading part for a cassette 2 at the front and is provided with the 1st supporting shafts 3 at both right and left sides of the rear part and also with the 2nd supporting shaft 3' at the right or left side of the front part. On the left-hand and right-hand sides of a chassis 8 equipped with a driving mechanism for the cassette 2, guide members 5 and 5' having long-sized hole parts 9 and 9 wherein the 1st and 2nd supporting shafts 3 and 3' are equipped movably and the 2nd long-sized guide hole 10 are provided. Further, the 2nd cassette support part 11 moving along an edge 12 extending forth and back is provided rotatably under the 1st cassette support member 1.