To provide a parameter determination method and a parameter determination device for a creep error compensation function that accurately compensates for a creep error.

A parameter determination device for a creep error compensation function includes a control device 3 including parameter determination means for determining a parameter used for an expression of a compensation function for calculating a creep error included in a load signal output from a load cell 1, and determined on the basis of a saturation amount of the creep error when a predetermined test load is placed on the load cell 1, and difference arithmetic means for calculating a difference between a load signal value immediately after the test load is placed on the load cell 1 for a period of time in which the creep error gets saturated and then removed, and a load signal value before the test load is placed, the parameter determination means being configured to determine the parameter while regarding the difference calculated by the difference arithmetic means as the saturation amount of the creep error.