Seat apparatus for vehicle

A seat apparatus for a vehicle (10) includes a seat for a vehicle (20), a seat driving portion (4) driving the seat (20) to change a seat position, a controlling portion (1) controlling an operation of the seat driving portion (4) to change the seat position to a predetermined position, and an input portion (2) receiving a control command relative to the controlling portion (1). The controlling portion (1) includes an assembly control mode in which an operation of the seat driving portion (4) is controlled on a basis of the control command input to the input portion (2) by an assembly input operation performed when the vehicle is assembled and includes a normal control mode in which the operation of the seat driving portion (4) is controlled on a basis of the control command input to the input portion (2) by a normal input operation performed when the vehicle is used by a user.