The present invention relates to an optical head for revealing near field through beams irradiated from a light source of a far field optical system, the optical head including: a flexible substrate made of a soft material and adapted to allow the optical head to be brought into close contact with a measured object and attached thereto even if the measured object has a curved or flat surface and a near-field revelation part located between the measured object and the flexible substrate in such a manner as to have one side brought into contact with the flexible substrate and the other side detachably attached to the measured object and adapted to reveal the near field through the beams irradiated from the light source.