An apparatus for checking an adherence state of fiber reinforced plastic tape includes an illuminating section having first and second illuminating groups. The main optical axes of illumination light beams of light emitting sections of the first illuminating group are set at a designated inclination angle with respect to a surface of an imaging region and distances on the main optical axes between a surface of a structural object and each of the light emitting sections are set to be the same. The main optical axes of illumination light beams of light emitting sections of the second illuminating group are set at an inclination angle different from the first illuminating group with respect to the surface of the imaging region and distances on the main optical axes between the surface of the structural object and each of the light emitting sections are set to be the same.