To provide a method for temporarily fixing optical members during the processing.

The composition comprises (A) polyfunctional (meth)acrylate, (B) monofunctional (meth)acrylate, (C) polysaccharides and (D) a photo-polymerization initiator. In a preferred embodiment, (C) the polysaccharides are swollen or dissolved by coming into contact with water at 30 to 90°C in the composition and more preferably both of (A) and (B) have the hydrophobic property in the composition. In the method for temporarily fixing optical members, the members are tentatively fixed by using the above composition, then the tentatively fixed members are processed, then the processed members are soaked into a warm water at less than 90°C and the hardened bodies of the composition are detached.