A cleaner comprising: a first cleaning module comprising a left spin mop and a right spin mop configured to come into contact with a floor while rotating in a clockwise direction or in a counterclockwise direction when viewed from an upper side; a second cleaning module configured to come into contact with the floor at a position spaced apart from the left spin mop and the right spin mop in a forward-and-backward direction; and comprising a rolling member configured to rotate about a rotation axis extending in a horizontal direction; a body supported by the first cleaning module and the second cleaning module ; and a controller configured to control autonomous travel of the cleaner, characterized in that the cleaner further comprises: a water supply module configured to supply water to the first cleaning module and comprising a water tank disposed inside the body ; and wherein the body is configured to move by rotation of at least one of the left spin mop, the right spin mop , or the rolling member without a separate driving wheel, and in order for the body to move straight forwards or In order for the body to stay in place, the left spin mop and the right spin mop are controlled to rotate to generate a forward-movement frictional force while the rolling member is controlled to rotate in a counterclockwise rotation direction when viewed from the right side to generate a backward-movement frictional force. a first cleaning module comprising a left spin mop and a right spin mop configured to come into contact with a floor while rotating in a clockwise direction or in a counterclockwise direction when viewed from an upper side; a second cleaning module configured to come into contact with the floor at a position spaced apart from the left spin mop and the right spin mop in a forward-and-backward direction; and comprising a rolling member configured to rotate about a rotation axis extending in a horizontal direction; a body supported by the first cleaning module and the second cleaning module ; and a controller configured to control autonomous travel of the cleaner, characterized in that the cleaner further comprises: a water supply module configured to supply water to the first cleaning module and comprising a water tank disposed inside the body ; and wherein the body is configured to move by rotation of at least one of the left spin mop, the right spin mop , or the rolling member without a separate driving wheel, and in order for the body to move straight forwards or In order for the body to stay in place, the left spin mop and the right spin mop are controlled to rotate to generate a forward-movement frictional force while the rolling member is controlled to rotate in a counterclockwise rotation direction when viewed from the right side to generate a backward-movement frictional force. a water supply module configured to supply water to the first cleaning module and comprising a water tank disposed inside the body ; and wherein the body is configured to move by rotation of at least one of the left spin mop, the right spin mop , or the rolling member without a separate driving wheel, and in order for the body to move straight forwards or In order for the body to stay in place, the left spin mop and the right spin mop are controlled to rotate to generate a forward-movement frictional force while the rolling member is controlled to rotate in a counterclockwise rotation direction when viewed from the right side to generate a backward-movement frictional force. <EOS>