Abstract: A semiconductor device and a method for manufacturing the same. The semiconductor device includes: a first gate-all-around (GAA) transistor disposed in the first region, including a first nanowire or nanosheet of at least one first layer, the at least one first layer and the substrate form a first group, among which all pairs of adjacent layers are separated by first distances, respectively; and a second GAA transistor disposed in the second region, including a second nanowire or nanosheet of at least two second layers, the at least two second layers and the substrate form a second group, among which the second layers are separated by second distances, respectively; where a minimum first distance is greater than a maximum second distance, and a quantity of the at least one first layer is less than a quantity of the at least two second layers.