To decrease the variations in mechanical characteristics and to suppress the deterioration of mechanical strengths with lapse of time.

A spacer layer 13 is formed on a substrate 11 formed with an electrode 12 on its surface and further, a latent image layer 18 is formed thereon. An aperture 15 is formed in the spacer layer 13 in a position adjacent to the latent image layer 18 to expose the electrode 12. Electroplating is thereafter executed with the electrode 12 as a cathode to form a plating layer 17 within the aperture 15 and on the latent image layer 18. Finally, the spacer layer 13 is removed and a cantilever 10a supported via a supporting strut 10b is manufactured on the substrate 11.