To easily determine a customer's preference.

A preference data processing device 10 uses cameras 1a, 1b-1n, nb to take images of dishes arranged on a table and a customer sitting at the table. From the images of dishes, meals in the dishes and leftovers are determined and stored in a customer table 162 as preference data. The customer's attributes are determined from the customer's image and the attribute data are stored in the customer table 162. The customer's attribute data and the preference data including the names of the meals which the customer ate and the names of the meals left over are printed and outputted as a report.