Headlamp control method and headlamp control device

A headlamp control device comprising a control unit for controlling a headlamp so as to regulate an irradiation amount, the headlamp being installed in a vehicle equipped with an autonomous driving mode driven in accordance with an image acquired by a visible light camera for capturing a circumference of the vehicle and a manual driving mode driven by a driver of the vehicle,

• the control unit being configured to:
• decrease the irradiation amount of the headlamp in the autonomous driving mode so as to be smaller than the irradiation amount of the headlamp in the manual driving mode;
• and
• when a fault in the autonomous driving mode is detected, set the irradiation amount to be equal to the irradiation amount in the manual driving mode until an operation of switching from the autonomous driving mode to the manual driving mode is completed.