To provide a merchandise sale system server and a merchandise sale method that provide an Internet shopping site capable of sufficiently ensuring a profit of a tenant manager offering merchandise and a profit of a system provider by suppressing price competition of merchandise.

The same pieces of merchandise in a plurality of tenants 3a' to 3c' are not managed by the respective tenants but managed together by the system provider 2'. When a user applies for purchase (1), one tenant is selected from among the plurality of tenants and an order for the merchandise is placed with the one tenant (2), and the merchandise is sold to the user.