Provided is a blood collection tube preparing apparatus which is simple, downsized, portable, capable of being easily placed on a desk or the like, excellent in responding to an emergency such as a disaster, and capable of preparing various kinds of blood collection tubes depending on a blood collection instruction from a doctor. A blood collection tube holding member is arranged along one transferring belt and between a forward-side transferring belt and a backward-side transferring belt of the one transferring belt, and lower end surfaces of a cap of a blood collection tube is supported on upper end surfaces of the blood collection tube holding member and the forward-side transferring belt. The forward-side transferring belt applies a transferring force to the blood collection tube through the cap. Further, the members constituting a storage box are accommodated in one module, and the storage box is detachably mounted onto a mounting portion of an apparatus main body. Further, the storage box is in the form of module, and hence an operation in the case of failure or during maintenance is significantly facilitated.
