VEHICLE MASS ESTIMATION DEVICE

The mass estimation unit is configured to: if an index dependent on the driving force does not vary beyond a first range from a first period through to a second period, and a variation from a first slope of the regression line that has been specified from a first data set acquired in the first period to a second slope of the regression line that has been specified from a second data set acquired in the second period exceeds a second range defined based on a variation of the index dependent on the driving force, reject the second slope, and otherwise estimate the mass of the vehicle based on the second slope.