To provide a self-adhesive sheet for retaining wafer which is a repeelable adhesive sheet having good expandability, by which chipping during dicing can be reduced and which has good repeelability without the reduction with the elapse of time and useful as a wafer-retaining sheet for dicing and the like.

The self-adhesive sheet for retaining a wafer is a self-adhesive sheet comprising 3 layers, that is, a base material layer comprising a thermoplastic resin and polymer particles having a multilayered structure, an intermediate layer comprising at least one resin selected from acrylic resins, polyamide resins and ethylene-vinyl alcohol resins and having 0.5-15 m thickness, and a radiation-curing type adhesive layer. In the sheet, the amount of migration of 2-15 functional compounds having 1,000-30,000 molecular weight to the base material layer after leaving the adhesive sheet at 50C for 2 weeks is 50%.