An active vibration isolating support device for preventing the direct transmission of vibrations from an engine to a vehicle body frame includes an electromagnetic actuator for driving a movable member in a reciprocating fashion to change the capacity of a first liquid chamber. A shaft portion of an armature driven by a coil is supported by a bearing so that it moves along an axis, whereby the size of an air gap can be maintained as small as possible, thereby making it possible to miniaturize the coil. In addition, a connecting rod for connecting the movable member with the armature is supported so as to sway relative to a coil spring and a saucer spring, whereby the vibration of the movable member is prevented from being transmitted to the shaft portion of the armature.