According to one embodiment, an optically transmissive metal electrode includes a plurality of first and second metal wires. The first metal wires are disposed along a first direction, and extend along a second direction intersecting the first direction. The second metal wires are disposed along a third direction parallel with a plane including the first and second directions and intersecting the first direction, contact the first metal wires, and extend along a fourth direction parallel with the plane and intersecting the third direction. A first pitch between centers of the first metal wires is not more than a shortest wavelength in a waveband including visible light. A second pitch between centers of the second metal wires exceeds a longest wavelength in the waveband. A thickness of the first and second metal wires along a direction vertical to the plane is not more than the shortest wavelength.