Provided is a method of provisional fixing which is remarkably effective in the dimensional accuracy of processed members. The method of provisional fixing comprises: a coating step in which a fixing member is coated with an adhesive for provisional fixing; a mounting step in which a member to be processed is mounted on the adhesive for provisional fixing; an irradiation step in which the adhesive for provisional fixing is irradiated with at least either visible rays or ultraviolet rays after the mounting step to heighten the adhesive force of the adhesive for provisional fixing; and a pressing step in which the fixing member and the member to be processed are pressed together from one side or both sides. The method of provisional fixing is characterized by simultaneously conducting the pressing step and the irradiation step for at least a certain time period. The adhesive for provisional fixing is a composition comprising a polyfunctional (meth)acrylate (A), a monofunctional (meth)acrylate (B), and a photopolymerization initiator (C).