Load port

There is provided a load port, including: a frame including an opening via which a transfer target object is capable of passing in a substantially horizontal posture; a load port door configured to engage with a container door capable of opening and closing a loading/unloading port of a storage container including slots capable of accommodating the transfer target object in a multi-stage manner, and to open and close the opening of the frame; and a mapping mechanism configured to map information on an accommodation state including presence or absence of the transfer target object in each of the slots in the storage container via the opening and the loading/unloading port.