To provide a vibration isolating device for a ship whereby vibration of auxiliary equipment of cabin, bed, chair, etc., and ship on board loaded object or the like can be suppressed, in the ship of intermediate and small size.

This device is constituted so as to provide an accelerometer 3 obtaining acceleration in orthogonal 3-axis direction of a ship on board object 2 relating to a ship main unit 1, at least six actuators 4 applying force in orthogonal 3-axis (x axis, y axis, z axis) direction and around each axis (θx, θy, θz), and a control circuit 5 performing a feedback of detected acceleration in the same direction of each axis relating to the actuator 4 (Ax, Ay, Az) in the orthogonal 3-axis direction to perform a feedback of detected acceleration in an axial direction different from each axial direction relating to the actuator 4 (Aθx, Aθy, Aθz). Here, by the control circuit 5, acceleration of reverse code to the detected acceleration is generated in the actuator 4, acceleration of the ship on board object 2 relating to the ship main unit 1 is reduced, vibration is isolated.