To provide a 'new handlebar device' capable of changing a bicycle having a 'conventional handlebar device' into a space-saving parked bicycle state quickly and easily by a 'one-hand on-touch system', and returning it into a general running bicycle state by a 'simpler restoration system', when a bicycle user has an umbrella or a baggage or one hand cannot be used owing to management of an infant or a pet.

A rolling mechanism 30 is provided on a joint portion between a handle cramp 11 and a handle post, and a mechanism is provided, in which each coupling member is provided on the handle cramp 11 and the handle post respectively, and connected mutually by a strong stopper so as to be opened.