An exhaust gas control apparatus removal determination device that performs an exhaust gas control apparatus removal determination processing based on a change in temperature of exhaust gas flowing into an exhaust gas control apparatus provided in an exhaust path of an engine and a change in temperature of exhaust gas flowing out. The controller determines whether the first state in which the difference between the measured value and the estimated value of the engine output is greater than or equal to a predetermined value continues for a predetermined time or longer, and determines that the engine output is in the first state. If it is determined, execution of the removal determination processing is prohibited.