A recording/reproducing apparatus includes a record medium cartridge holder having
a main support portion with a cartridge carrying portion slidably arranged on it
for withdrawing a cartridge held at a standby position to a withdrawal position.
An insertion restricting portion prohibits passage of a cartridge in an improper
orientation. A lock portion, arranged directly above the insertion restricting
portion, locks the carrying portion in the standby position and releases the locking
of the carrying portion when the cartridge passes through the insertion restricting portion.
