The present invention is intended to provide a gel sheet having a formulation providing an adhesive force on the skin side suitable for the skin (i.e., a gel having a low adhesive force and being able to withstand a tip pressure of a terminal and the like), and concurrently having a sufficient adhesive force against an electrode element on the side opposite to the skin side. The present invention is a gel sheet having a laminated structure of a layer A and a layer B, characterized in that the storage elastic modulus of the layer A at 23° C. and 10 Hz is 12,000 to 40,000 Pa, and the storage elastic modulus of the layer B at 23° C. and 10 Hz is 2,000 to 10,000 Pa.