To obtain the coupling support device in a rolling mill having simple construction, easy inspection and improved applicability by setting a support arm, having an appropriate shape extending downward from turning support point, at the position to receive the peripheral face of rear face side of a coupling for its rotating position and a position to retreat obliquely downward therefrom.

When executing roll change work, support arms 9a, 9b are turned counterclockwise around pins 1a, 1b by advancing action of the rod of a cylinder 9d. Thus, the support arms 9a, 9b are set to the position in the figure for the couplings 7, 8 arranged up/down as taking one cylinder 9d for a drive source, these couplings are held up to completing roll change. After completing roll change, by retreating the rod of cylinder 9d, the support arms 9a, 9b are turned clockwise around the pins 1a, 1b and are returned to retreated position.