A method of detecting deposition in an exhaust pump for exhausting gas by a rotational movement of a rotating body driven by a motor, the deposition detection method comprising the steps of: as an initial process: recognize a stabilization of a motor current over a predefined time period, and upon this recognition, to execute the following four steps; read the motor current value of the motor a plurality of times; calculate a motor current average value of the motor based on the read motor current values of the motor; determine a motor current initial value based on the motor current average value of the motor; and store the determined motor current initial value; and as a subsequent process after the initial process and after an operation of the exhaust pump for a predetermined period: recognize a stabilization of a motor current over a predefined time period, and upon this recognition, to execute the following five steps; read the motor current value of the motor a plurality of times; calculate the motor current average value of the motor based on the read motor current values of the motor; determine a motor current present value based on the motor current average value of the motor; and determine an amount of change between the motor current present value and the motor current initial value, detect a deposition in the exhaust pump based on the amount of change after the operation of the exhaust pump for the predetermined period. as an initial process: recognize a stabilization of a motor current over a predefined time period, and upon this recognition, to execute the following four steps; read the motor current value of the motor a plurality of times; calculate a motor current average value of the motor based on the read motor current values of the motor; determine a motor current initial value based on the motor current average value of the motor; and store the determined motor current initial value; and recognize a stabilization of a motor current over a predefined time period, and upon this recognition, to execute the following four steps; read the motor current value of the motor a plurality of times; calculate a motor current average value of the motor based on the read motor current values of the motor; determine a motor current initial value based on the motor current average value of the motor; and store the determined motor current initial value; and as a subsequent process after the initial process and after an operation of the exhaust pump for a predetermined period: recognize a stabilization of a motor current over a predefined time period, and upon this recognition, to execute the following five steps; read the motor current value of the motor a plurality of times; calculate the motor current average value of the motor based on the read motor current values of the motor; determine a motor current present value based on the motor current average value of the motor; and determine an amount of change between the motor current present value and the motor current initial value, recognize a stabilization of a motor current over a predefined time period, and upon this recognition, to execute the following five steps; read the motor current value of the motor a plurality of times; calculate the motor current average value of the motor based on the read motor current values of the motor; determine a motor current present value based on the motor current average value of the motor; and determine an amount of change between the motor current present value and the motor current initial value, detect a deposition in the exhaust pump based on the amount of change after the operation of the exhaust pump for the predetermined period.