A cutting insert has a first end surface and a second end surface which are opposed to each other. The first end surface has at least one apex and two side edges which extend so as to sandwich the apex. At least part of the two side edges serves as a cutting edge. The first end surface has a rake surface which is connected to the cutting edge. As viewed in a cross-section which intersects with the two side edges and which is orthogonal to the second end surface, the rake surface is inclined relative to the second end surface.