This paper describes development of a compliance mechanism for an aerial manipulator to contact bridge in bridge inspection. Our unmanned aerial vehicle (UAV) with three degree of freedom (DoF) manipulator is developed to hammer bridges in inspection. The compliance mechanism absorbs the movement of the UAV to contact to the wall stably. An experiment shows that compliance mechanism enables a contacting part of an end effector to contact wall vertically while the end effector is 58 [deg] to the wall. The contact force can be controlled with 0.49 [N] error with the compliance mechanism.