Provided is a demand prediction device (10) comprising: management units (101, 102) that, with respect to a product sold at a plurality of stores, manage special sales scheduling information that indicates a scheduled special sales quantity based on special sales of the product by each store, and past results information that indicates past sales results quantities for each store relating to the product, the past sales results quantities including, with regard to the product, sales results quantities based on special sales and sales results quantities based on ordinary sales; and a prediction unit (103) that estimates, along with a demand prediction quantity from ordinary sales, a quantity obtained by totaling the sales results quantity for each store, said quantity being obtained by subtracting a sales results quantity of a portion exceeding a prescribed threshold from a past sales results quantity for each store relating to the product included in past results information, and adds, to the estimated demand prediction quantity based on ordinary sales, the scheduled special sales quantity based on special sales, thereby predicting a demand prediction quantity of the product for a first prescribed time period at a site that manages the product that is delivered to the plurality of stores.