A plant performance evaluation apparatus includes a first storage storing a first static model indicating a model of a first steady state in a plant, a second storage storing a first dynamic model indicating a model of a dynamic state of the plant, a model converter configured to convert the first dynamic model to a second static model indicating a model of a second steady state of the plant, and to store the second static model into the first storage, the first steady state indicating a steady state of the plant temporally before the second steady state, a comparator configured to compare parameters included in the first static model with parameters included in the second static model and to output a comparison result, and a display configured to display the comparison result output from the comparator.
