In a movable seat for a vehicle, there are provided a seat body shiftable between inside and outside the vehicle passenger compartment, a seating member attached to the seat body to be movable between a first position where a sitter such as a humanoid biped robot is seated or unseated and a second position where the sitter is maintained seated, such that a location of a center of gravity of the sitter, when seated in the first position, with respect to a position of feet of the sitter is in a predetermined relationship, and a controller controlling an actuator to move the seating member toward one of the first and second positions in response to the inputted instruction, thereby enabling reliable seating, unseating, boarding and alighting, not only of elderly persons and others requiring special care but also of the humanoid robot.