An inserting and retrieving mechanism of a "Juke Box" type disc memory device includes a movable body which has pushing members adapted to push a cartridge into a stocker or a recording and reproducing device of the disc memory device and a pair of clampers adapted to pull out the cartridge from the stocker or recording and reproducing device in association with engaging recesses formed on the cartridge, a driving means for opening and closing the clampers through a toggle means arranged symmetrically about the driving means, a first position sensor provided on the inserting and retrieving mechanism for detecting a position of a rear end of the cartridge when it reaches a position in which the clampers are ready to clamp the cartridge and a second position sensor provided in the stocker and/or the recording and reproducing device for detecting a position of a front end of the cartridge when it reaches a position in which the cartridge is ready to be released. The inserting and retrieving mechanism may have a pair of cartridge holding portions so that a pair of cartridges are to be handled, simultaneously.