The purpose of the present invention is to provide a cutting insert which can minimize friction with a chip and maximize heat-radiating performance. To this end, the present invention provides a cutting insert comprising: an upper surface; a lower surface; a plurality of lateral surfaces for connecting the upper surface with the lower surface; a main cutting edge formed between the lateral surface and the upper surface; and a main cutting edge land and a main cutting edge incline formed in series between the main cutting edge and the upper surface, wherein the main cutting edge incline has a first wavy shape in which two or more incline convex parts and two or more incline concave parts are repeated from the main cutting edge land toward the upper surface.

A cutting insert, a cutting tool and method of manufacturing a machined product. The cutting insert includes: upper and lower surfaces; a side surface; a cutting edge; and a rake portion on the upper surface. The cutting edge includes major and minor cutting edges that are convex toward outside of the main body portion. The minor cutting edge has a curvature radius smaller than a curvature radius of the major cutting edge. The rake portion is inclined and approaches the lower surface as moving from the major cutting edge toward inside of the main body portion and is located along the major cutting edge. An inclination angle of the rake portion becomes smaller as moving from a part continuous with one end of the major cutting edge toward a part continuous with center of the major cutting edge.