A method for manufacturing a stabilizer, the stabilizer including a main body bar that is elastically deformable, and a pair of connecting plates that are separately connected to a pair of left and right suspension devices, the method including a forging step of forming the connecting plate by forging both end portions of a material tube, in which in the forging step, both end portions of the material tube are crushed in a radial direction to be formed into the connecting plate in a state where a sealing metal plate heated to a temperature equal to or higher than a melting point is disposed inside both end portions of the material tube heated to a temperature lower than the melting point.