An optical hair-growing device includes a headset that outputs light, and a controller that controls operation of the headset. The headset includes a light emitting unit including a light source, a pair of arms attached to the light emitting unit, a pair of first attachments attached to the arms to produce reaction force, and a pair of second attachments attached to the light emitting unit to produce reaction force. When the headset is attached on a head, the pair of first attachments each comes into contact with a side head portion to give the reaction force to the head, and the pair of second attachments each comes into contact with a head top portion to give the reaction force to the head. According to the present constitution, a position of the light emitting unit with respect to the head is hard to be displaced.
