PROBLEM TO BE SOLVED: To provide a force detection device capable of calculating a force in a tangential direction with respect to a contact surface.SOLUTION: A force detection device 11 includes: a support member 6； a pair of fluid bags B1 and B2； a fluid bag BS； a pair of pressure sensors S1 and S2； and a calculation part C. The fluid bag BS is disposed at the side opposite the side where the fluid bags B1 and B2 are in contact with a support member 6 neighboring to both fluid bags B1 and B2. The calculation part C acquires a piece of information relevant to an internal pressure of the fluid bags B1 and B2 from the pressure sensors S1 and S2. The calculation part C calculates a force which acts on the contact surface CS between an object and the fluid bag BS in a tangential direction based on a difference between the internal pressure of the fluid bag B1 and the internal pressure of the fluid bag B2 when an external force is applied to the fluid bag BS from the object.SELECTED DRAWING: Figure 9
