To provide an entrance base enabling a person to go up and down a step part existent in a building with ease and capable of guiding a person's feet onto a foothold board securely.

When a person approaches the entrance base 10 installed at the entrance A from the outdoor side, a light emitting element 18b of a sensor unit 18 attached to a front side frame board 13 is lit based on a detection signal output from a human detection sensor 18a of the sensor unit 18 attached to the front side frame board 13. When a person approaches the entrance base 10 installed at the entrance A from the indoor side, a light emitting element 18b of the sensor unit 18 attached to right and left end parts of the foothold board 11 is lit based on a detection signal output from the human detection sensor 18a of the sensor unit 18 attached to the foothold board 11. Consequently, it is possible to guide person's feet onto the foothold board 11 of the entrance base 10 installed at the entrance A securely.