In a magnetic tape device, a tape cassette moving table 4 is placed between a pair of right and left guide plates 3a and 3b so as to be movable forward and backward (a and b). Rocking levers 8 which are engaged with the moving table 4, and a rotating cam 9 which is forward and reversely rotated by a driving source are interlockingly connected to each other via a slide plate 26. The rocking levers 8 are swung forward and backward (c and d) by the driving source via the rotating cam 9 and the slide plate 26 to move the moving table 4 forward and backward (a and b) between a cassette inserting position A and a cassette placing position B.