Provided is a laminated body comprising a substrate to be ground and a support, where the substrate is ground to a very small thickness and can then be separated from the support without damaging the substrate. One embodiment of the present invention is a laminated body comprising a substrate to be ground, a joining layer in contact with the substrate to be ground, a photothermal conversion layer comprising a light absorbing agent and a heat decomposable resin, and a light transmitting support. After grinding the substrate surface which is opposite that in contact with the joining layer, the laminated body is irradiated through the light transmitting layer and the photothermal conversion layer decomposes to separate the substrate and the light transmitting support.