To provide a bridge construction method and the device in which the space of a jobfield is saved, the environmental destruction in the jobfield is restrained at a minimum, stress check and reinforcement of a bridge girder is not required, temporary facilities for construction are enough to be a few, and decrease of cost can be attained.

A pair of bridge girders 10A, 10B to be bridged onto bridge piers 1A, 1C positioned on both sides of one bridge pier 1B are vertically assembled along the bridge pier 1B. Next, a pair of the bridge girders 10A, 10B are respectively tilted centering around the lower end parts supported on the lower end side of the bridge pier 1B so that the upper end parts as the rotating ends are supported on the upper ends of the bridge piers 1A, 1C on both sides, then while sliding a pair of the bridge girders 10A, 10B respectively centering around the upper end parts supported with the upper ends of the bridge piers 1A, 1C on both sides so as to separate the upper end parts from the bridge girder 1B, and the lower end parts are hoisted so as to be supported with the upper end of the bridge pier 1B.