A ratchet wrench that comprises: a functional head and a handle connected to each other capable of relative rotation around a hinge axis; a ratchet wheel coaxial with said hinge axis, rigidly attached to the functional head and provided with circumferential teeth along at least part of a peripheral edge thereof; a ratchet pawl movably installed on the handle and provided with at least a restraining tooth engageable to said circumferential teeth of the ratchet wheel; an elastic working element that biases said ratchet pawl to an engaged position with said circumferential teeth of said ratchet wheel; a releasing member movably installed on the handle and manually operable between a rest position and a release position; a kinematic chain arranged between said releasing member and said ratchet pawl, wherein said kinematic chain transforms a movement of the releasing member from said rest position to said release position into a movement of the ratchet pawl to a position out of engagement with the ratchet wheel against the bias of said elastic working element,; and a locking element movably installed on the handle, said locking element being manually operable between a rest position, in which the locking element does not interfere with the ratchet pawl, and a locking position, characterized in that: the locking element in said locked position contacts the ratchet pawl and holds the ratchet pawl in said engaged position with the ratchet wheel; the locking element is slidingly installed in a cavity of the handle and has a protrusion; and said cavity has a first recess in which said protrusion fits when the locking element is in said rest position, and a second recess in which the protrusion fits when the locking element is in said locking position. a functional head and a handle connected to each other capable of relative rotation around a hinge axis; a ratchet wheel coaxial with said hinge axis, rigidly attached to the functional head and provided with circumferential teeth along at least part of a peripheral edge thereof; a ratchet pawl movably installed on the handle and provided with at least a restraining tooth engageable to said circumferential teeth of the ratchet wheel; an elastic working element that biases said ratchet pawl to an engaged position with said circumferential teeth of said ratchet wheel; a releasing member movably installed on the handle and manually operable between a rest position and a release position; a kinematic chain arranged between said releasing member and said ratchet pawl, wherein said kinematic chain transforms a movement of the releasing member from said rest position to said release position into a movement of the ratchet pawl to a position out of engagement with the ratchet wheel against the bias of said elastic working element,; and a locking element movably installed on the handle, said locking element being manually operable between a rest position, in which the locking element does not interfere with the ratchet pawl, and a locking position, the locking element in said locked position contacts the ratchet pawl and holds the ratchet pawl in said engaged position with the ratchet wheel; the locking element is slidingly installed in a cavity of the handle and has a protrusion; and said cavity has a first recess in which said protrusion fits when the locking element is in said rest position, and a second recess in which the protrusion fits when the locking element is in said locking position.