To provide a control apparatus capable of easily and tightly assembling transparent parts which transmit light for indication or light projection/ reception, without requiring the design at a high dimensional accuracy or needing any large apparatus or jig for assembling and is advantageous in the assembling man-hour and cost.

Transparent parts, i.e., lens fibers 3 are inserted and held in a window 2 of a case to face at light emitting devices 6 while protrusions 9 formed on the fibers 3 are butted to a circuit board 4 fixed to the interior of the case to thereby assemble the fibers 3 in the case.