Provided is a foamed silicone sheet which can exhibit excellent bubble-removability, has good adhesion to an object to which the sheet is to be attached, has good sealability, maintains the ability toexhibit these effects even when the thickness of the sheet is reduced, can preferably exhibit a stable modulus of elasticity over a low to high temperature range, and can have a low level of compression set in both a low-temperature range and a high-temperature range. Also, provided is a foamed silicone sheet composite having such a foamed silicone sheet. Furthermore, provided is a method for producing such a foamed silicone sheet. The foamed silicone sheet according to the present invention has a thickness of 10-3000 [mu]m and an open-cell structure in which the open-cell proportion is 90% or more, the average cell size is 1-50 [mu]m, and 90% or more of all cells have a cell size of 80 [mu]m or less.