In a throttle valve control device, an engine required output setting section sets an engine required output corresponding to an accelerator opening degree by means of selecting a characteristic which is varied depending on a road surface friction coefficient or by means of interpolation calculation based on a road surface friction coefficient. An engine required torque setting section sets an engine required torque based on an engine speed and the engine required output. A throttle opening degree setting section sets a throttle opening degree based on the engine speed and the engine required torque and outputs a signal corresponding to the throttle opening degree to a throttle motor.