There is provided a method of manufacturing a semiconductor device which, in the case where an InP-based device is formed with a sacrificial layer in between, is capable of obtaining better device characteristics than those in the case where an AlAs single layer is used as the sacrificial layer, and which does not have the possibility that the device layer is etched together with the sacrificial layer during etching of the sacrificial layer. A method of manufacturing a semiconductor device includes: a formation step of forming a sacrificial layer which is pseudomorphic to InP on an InP substrate, and then forming an InP-based device layer on the sacrificial layer; and a separation step of separating the InP substrate and the device layer from each other by etching the sacrificial layer.