An irradiating direction control apparatus includes a storing portion for storing a design reference value of a vehicle and storing output voltages of vehicle height sensors when the vehicle is in a reference attitude as measured reference values, an operating portion for operating a reference vehicle height based on the measured reference value and the design reference value and operating a pitch angle of the vehicle based on detected outputs of the vehicle height sensors and the reference vehicle height and the design reference value, and a deflection control portion for controlling to deflect an irradiating direction of a lamp based on the operated pitch angle. Even when the design reference value of the vehicle is stored to the storing portion at a later step of steps of assembling the vehicle, the reference vehicle height can be operated by the output voltages and the design reference value and initialization based on the reference vehicle height can be realized. A degree of freedom of design of a factory layout is promoted and a production efficiency is promoted.