A seamless can body in which the flatness of a center panel of a bottom of the thin can body can be stably maintained and the can body has high pressure resistance, high formability, and excellent properties for an internal pressure test. The seamless can body has a can bottom shape having a rim portion protruding to an outside of the can, an annular concave portion protruding to an inside of the can, and a flat center panel extending continuously from an inner peripheral side of the annular concave portion with a corner portion interposed therebetween. The curvature radius (R3) of the corner section is in the range of 1.5 mm