A fixing mechanism includes a base, a substrate and a latch. This structural stiffening or reinforcing of the airfoil allows for reducing bending stress that may be produced from internal or external pressurization of the airfoil without incurring any substantial thermal stress. A pressurizing means is provided for applying a predetermined pressure to the microchannel and the cantilever is moved with its tip to the microscopic object to be spatially manipulated. For a light recording medium having a narrow groove pitch, the difference between a main beam push-pull signal and a first sub beam push-pull signal is set as a track error signal.