Rotor blade and axial flow rotating machine with the same

A rotor blade comprising:

• a blade body which has an airfoil shape;
• and
• a shroud cover which is formed at a first end portion on a first side inside the blade body between the first and second sides of the blade body in a blade height direction, wherein
• the shroud cover extends in a first direction intersecting the blade height direction and separating away from a camber line in the first end portion of the blade body,
• the shroud cover comprises a gas path surface exposed to an outside toward the second side, and a back surface which is opposite to the gas path surface and which is exposed to an outside toward the first side,
• the gas path surface comprises a fillet surface which gradually extends toward the first side as it separates from each of a pressure surface and a suction surface of the blade body in the first direction in a cross-section orthogonal to the camber line, and
• the back surface comprises a recessed surface which extends so as to be recessed toward the second side along at least a part of a surface of the fillet surface in the cross-section.