To provide a method of manufacturing a semiconductor device in which the space between semiconductor films transferred at plural locations is narrowed. A first bonding substrate having first projections is attached to a base substrate. Then, the first bonding substrate is separated at the first projections so that first semiconductor films are formed over the base substrate. Next, a second bonding substrate having second projections is attached to the base substrate so that the second projections are placed in regions different from regions where the first semiconductor films are formed. Subsequently, the second bonding substrate is separated at the second projections so that second semiconductor films are formed over the base substrate. In the second bonding substrate, the width of each second projection in a direction (a depth direction) perpendicular to the second bonding substrate is larger than the film thickness of each first semiconductor film formed first.