To restrain vibration of a specific frequency transmitted to a structure.

This vibration transmission restraining device 1 is installed in the structure 13, and supports the structure 13. The vibration transmission restraining device 1 has a cylinder 2 and a piston 3 arranged in the cylinder 2. A space surrounded by the piston 3 and the cylinder 2 is a fluid chamber 21, and air is filled inside. The piston 3 supports the structure 13 by pressure generated by the air. The fluid chamber 21 is connected with a fluid passage 7 communicating the fluid chamber 21 with the outside. The fluid passage 7 is provided with an opening-closing valve 8V. The opening-closing valve 8V is opened and closed by the frequency of the vibration undesired to be transmitted to the structure 13, and exhausts the air in the fluid chamber 21 to the outside.