To provide a pattern forming method for a field effect transistor by which a resist layer having a two-layer structure can be exposed by a single exposure, good throughput is ensured and a gate of <0.1 μm having a stable sectional shape is obtained.

The pattern forming method includes a step for forming a first resist layer on a substrate, a step for forming a chemical amplification type second resist layer having higher sensitivity than the first resist layer on the first resist layer, a step for carrying out exposure in such a way that the first resist layer is sufficiently exposed and a step for successively developing the second resist layer and the first resist layer. An opening having a smaller size than an opening formed in the second resist layer is formed in the first resist layer.