A holder device is capable of automatically adjusting orientation of an electronic device placed thereon based upon position of a user. The holder device includes a holder body, a torque unit, and a control unit. The holder body includes a base, a movable arm set pivoted to the base, and a fastening seat for placing the electronic device thereon. The torque unit is disposed at pivot joints of the movable arm set and provides power for driving pivoting movement of the movable arm set. The control unit is disposed to receive user-associated position information and is configured to generate a control command corresponding to the position information and to transmit the control command to the torque unit so as to control the torque unit to move the movable arm set for adjusting orientation of the electronic device placed on the fastening seat.