To correctly execute measurement of a pitch between V-grooves after forming V-groove formation in an optical fiber fixing member by use of contactless optical image detection means.

For inspecting an optical fiber fixing member obtained by simultaneous press-work to a flat part at the bottom part of a V-groove, a V-groove block 1 is detachably and immovably disposed to expose the V-groove, a CCD camera 10 is moved to be roughly perpendicular to length direction of the V-groove, distance from a reference position to a left side trough part and a right side trough part is measured, a center position of the V-groove is operated based on differential distance, an absolute position of the CCD camera 10 is measured, and a pitch P between the V-grooves is operated based on the center position and the absolute position.