Disclosed is a semiconductor device. The semiconductor device comprises a first epitaxial layer, a second epitaxial layer, a first source/drain region and a second source/drain region, a first channel, a first gate stack, a second channel, and a second gate stack, wherein the first epitaxial layer is arranged on a substrate; the second epitaxial layer is arranged on the first epitaxial layer; the first source/drain region and the second source/drain region are in the first epitaxial layer and the second epitaxial layer; the first channel is formed by the second epitaxial layer between the first source and drain regions; the first gate stack is arranged on the first channel; the first source/drain region, the first channel and the first gate stack form a first device; the second channel is formed by the first epitaxial layer between the second source and drain regions; the second gate stack is arranged on the first channel; and the second source/drain region, the second channel and the second gate stack form a second device. According to the semiconductor device and a manufacturing method therefor disclosed by the invention, one of the two epitaxial layers stacked on the substrate is removed through selective etching; and the channels of different materials are formed by NMOS and PMOS, so that the carrier mobility and CMOS driving capability are improved simply and effectively.