A commodity search device includes a storage unit, a measuring unit, a number input unit, a unit average weighing value calculator, and a first commodity search unit. The storage unit stores commodity information including a reference unit weight determined for each commodity. The measuring unit measures a total weight of commodities placed at a predetermined weighing position. The number input unit allows inputting the number of the weighed commodities. The unit average weighing value calculator divides the total weight of the commodities weighed by the measuring unit by the number input by the number input unit to calculate a unit average weighing value per one commodity. The first commodity search unit searches for commodities falling within a weight deviation from the storage unit using the unit average weighing value.