A container holder includes a holder body, a supporting member, an actuator, and a switch. The supporting member is disposed movably to the holder body. The holder body demarcates an accommodation space for accommodating or holding a container therein partially. The actuator includes a first actuating unit, being made of a ferromagnet, and a second actuating unit, being made of an electromagnet. Moreover, one of the actuator's first actuating unit and second actuating unit is fixed to the holder body, and the other one of the actuator's first actuating unit and second actuating unit is fixed to the supporting member. The switch turns on and off the actuator's second actuating unit to have the electromagnet produce and lose an electromagnetic force. The resulting electromagnetic force moves the supporting member to come in and/or come out of the holder body's accommodation space.