A wafer supply device (20, 220) configured to supply a wafer divided into multiple dies to a supply position, the wafer supply device (20, 220) comprising: a die information storage section configured to store the number of the dies for each rank allocated to each of the dies; a block information acquisition section configured to acquire a condition of the dies to be mounted on a block provided on a board to be conveyed, wherein the block constitutes a mounting position of the dies on an upper surface of the board; a required block number acquisition section configured to acquire a required number of the dies to be mounted on the block; a producible number calculation section configured to calculate the number of the producible blocks based on a content stored in the die information storage section and a content which is acquired by the block information acquisition section and the required block number acquisition section and a lot information storage section configured to store the number of the dies, which are included in a lot having one wafer or multiple wafers, for each rank, characterized in that the wafer supply device further comprises: a scheduled number acquisition section configured to acquire a scheduled production number of the blocks; and a production propriety determining section configured to determine whether the lot stored in the lot information storage section includes the dies sufficient to produce the scheduled production number of the blocks acquired by the scheduled number acquisition section. a die information storage section configured to store the number of the dies for each rank allocated to each of the dies; a block information acquisition section configured to acquire a condition of the dies to be mounted on a block provided on a board to be conveyed, wherein the block constitutes a mounting position of the dies on an upper surface of the board; a required block number acquisition section configured to acquire a required number of the dies to be mounted on the block; a producible number calculation section configured to calculate the number of the producible blocks based on a content stored in the die information storage section and a content which is acquired by the block information acquisition section and the required block number acquisition section and a lot information storage section configured to store the number of the dies, which are included in a lot having one wafer or multiple wafers, for each rank, characterized in that the wafer supply device further comprises: a scheduled number acquisition section configured to acquire a scheduled production number of the blocks; and a production propriety determining section configured to determine whether the lot stored in the lot information storage section includes the dies sufficient to produce the scheduled production number of the blocks acquired by the scheduled number acquisition section. a scheduled number acquisition section configured to acquire a scheduled production number of the blocks; and a production propriety determining section configured to determine whether the lot stored in the lot information storage section includes the dies sufficient to produce the scheduled production number of the blocks acquired by the scheduled number acquisition section.