A fluid sealed type vibration insulating device provided with an actuator for generating an active supporting force. The vibration insulating support device includes a main fluid chamber defined by a conical-shaped elastic support and a movable construction part. The movable construction part is constituted by a partition wall and a magnetic path member which is fastened to the partition wall through a clearance spacer. Therefore, a clearance is formed between the partition wall and the magnetic path and a plate spring is installed in the clearance to support the movable plate against the magnetic force of a permanent magnet. The partition wall has an internal thread hole to be bolted. The magnetic path has a hole with one opening diameter larger than another opening diameter for inserting a bolt. The bolt has a dish-shaped bolt head. If a center of the hole is off to the side of the center of the partition wall's hole, any edge point of the bolt head contacts any surface of the inner hole and pushes. Therefore, the center of the magnetic path member 88 is automatically put in alignment with the center of the partition wall 78A by the bolt.