A headlamp apparatus for a vehicle accurately detects a straight steering position in a steering device of the vehicle, thereby controlling a light distribution characteristic of a headlamp of the vehicle. In a headlamp apparatus for a vehicle including a controller for controlling a light distribution of a headlamp based on a steering angle of a steering device of the vehicle, the controller detects a straight steering position based on an origin position signal obtained when each of wheel speeds SPDL and SPDR of left and right wheels (front wheels 3LF and 3RF) of the vehicle is at least a reference value α and a difference in the speed is equal to or lower than a reference value β on the basis of an origin position signal PZ to be output from the steering device for each rotation of a steering wheel and the difference in the speed.