PURPOSE: To obtain the rigid, small-sized corner cube of simple structure which maintain a degree of polarization by combining components in a specific shape together.

CONSTITUTION: The cross sectional shape of a component 2 is sectorial having a center angle α=120°. The surface vector of one lengthwise end surface forming a reflecting surface is contained in a surface which bisecting the center angle α and the tilt angle of the reflecting surface 2a to a center axis 2b along the rigid line of the center angle α is tan-1(1/21/2). Threed components 2 mentioned above are assembled in contact with respective flanks 2c. Consequently, all entire reflecting surface are effective surfaces and a cylinder for fixing the corner cube may be simply cylindrical.