A vehicle door drive apparatus (300, 800), comprising: an input unit configured to input a command for automatically opening a door of a vehicle in a fully closed state by a predetermined amount that does not bring the door to a fully open state; a door drive unit configured to automatically open the door; a determination unit configured to determine, when the command is input by the input unit, the predetermined amount depending on a state of a user or a state of the vehicle; and an open operation unit configured to control the door drive unit so as to automatically open the door by the determined predetermined amount from the fully closed state, characterized in that the input unit comprises: a first input unit provided on the door on an outer side of the vehicle; a second input unit provided on the door on an inner side of the vehicle; and an inclination sensor configured to detect the inclination angle of the vehicle corresponding to the inclination in a door open direction of the vehicle; the state of the user comprises whether the command is input on the first input unit or input on the second input unit, and the state of the vehicle comprises the angle of inclination of the vehicle detected by the inclination sensor; and the determination unit is configured to change the predetermined amount between a case in which the command is input on the first input unit and a case in which the command is input on the second input unit, or according to the inclination of the vehicle. an input unit configured to input a command for automatically opening a door of a vehicle in a fully closed state by a predetermined amount that does not bring the door to a fully open state; a door drive unit configured to automatically open the door; a determination unit configured to determine, when the command is input by the input unit, the predetermined amount depending on a state of a user or a state of the vehicle; and an open operation unit configured to control the door drive unit so as to automatically open the door by the determined predetermined amount from the fully closed state, characterized in that the input unit comprises: a first input unit provided on the door on an outer side of the vehicle; a second input unit provided on the door on an inner side of the vehicle; and an inclination sensor configured to detect the inclination angle of the vehicle corresponding to the inclination in a door open direction of the vehicle; a first input unit provided on the door on an outer side of the vehicle; a second input unit provided on the door on an inner side of the vehicle; and an inclination sensor configured to detect the inclination angle of the vehicle corresponding to the inclination in a door open direction of the vehicle; the state of the user comprises whether the command is input on the first input unit or input on the second input unit, and the state of the vehicle comprises the angle of inclination of the vehicle detected by the inclination sensor; and the determination unit is configured to change the predetermined amount between a case in which the command is input on the first input unit and a case in which the command is input on the second input unit, or according to the inclination of the vehicle.