A thermally-assisted magnetic recording head enables even steeper magnetization reversal between adjacent magnetic domains of a magnetic recording medium and satisfies the demand for high SN ratio and high recording density. The thermally-assisted magnetic recording head includes a pole that generates a writing magnetic field from an end surface that forms a part of an air bearing surface that opposes a magnetic recording medium, a waveguide through which light for exciting surface plasmon propagates, and a plasmon generator that couples to the light in a surface plasmon mode. The plasmon generator has a plane part and a projection part, the pole has a projection part opposing surface that opposes the projection part, and the distance between the projection part opposing surface and the projection part is 10-40 nm.