PURPOSE: To obtain an automatic bottom cover opening/closing mechanism of a chip storage container capable of efficiently transferring a large quantity of chips contained therein into a transport container at a time without a possibility of missing.

CONSTITUTION: A hang-down bracket 34 integrally formed on the outer surface of a bottom cover of a chip storage container 10 is hinged to the chip storage container 10 in the vicinity of the bottom edge thereof through a shaft pin 38. A rotating roller 56 engaged with a trigger projection 57 on the inner surface of a transport container is provided in relation to the hang-down bracket. The rotating roller is pressed by a spring so as to be projected outward to a certain extent from the side part of the storage container. A latch hook 60 is pivotally mounted on the side part of the chip storage container so as to be pressed inward by a spring in a normal state. The latch hook comprises a hooking part 62 releasably hooking a part of the peripheral edge of the bottom cover of the chip storage container at the bottom cover hooking/closing position thereof and a shoulder part 64 making the latch hook pivot outward against the pressing force of the spring by engaging with a trigger projection 44 provided on the inner surface of the transport container.