PROBLEM TO BE SOLVED : To provide information regarding fluctuation of profit in a sublease contract.SOLUTION : The data processor 1 provides information regarding profit of a customer such as an owner of real estate in the sublease contract by newly setting and calculating an owner profit amount of a next section of the sublease contract on the basis of an acquisition ratio, an expense ratio, and an actual total rent of a prior section. Consequently, since information regarding profit per each section when carrying out the sublease contract or information regarding profit when conditions of the sublease contract are changed or the like can be clearly presented to the customer such as the owner of the real estate, a situation of entanglement in a negotiation to change an expected total rent of each section in the sublease contract can be prevented. A situation of a sublessor suffering loss from bearing all of the difference between the expected total rent and the actual total rent due to the negotiation not being settled can also be avoided.