PROBLEM TO BE SOLVED : To smoothly perform changeover of payment schemes by changing over a payment scheme of rents with respect to a real estate management company, which has concluded a lease contract of a real estate property with a tenant, only by switching guarantee companies.SOLUTION : A guarantee management device 24 includes : a storage device 101; a rewriting part 102; a reading part 103; scheme distribution parts 104 and 106; a credit information acquisition part 105; a settlement request signal output part 107; and a settlement processing part 108. The scheme distribution part 104 receives scheme information S read from the storage device 101 by the reading part 103, and determines whether the scheme information S is a first scheme A, a second scheme B, or a third scheme C. When the scheme information S is the first scheme A, the second scheme B, and the third scheme C respectively, then, correspondingly, the credit information acquisition part 105, the settlement request signal output part 107, and the settlement processing part 108 are actuated respectively.