Washing machine

A washing machine comprising:

• a body configured to have an inlet formed in a front surface thereof;
• a washing tub configured to be rotatably disposed in the body, accommodate a laundry injected through the inlet therein, and have a cylindrical shape;
• and
• a plurality of protruding portions configured to protrude from an inner circumferential surface of the washing tub toward an inner portion of the washing tub to form a pattern,
• wherein each protruding portion, of the plurality of protruding portions, includes a front end portion adjacent to the inlet, a central portion connected to the front end portion and a rear end portion connected to the central portion,
• wherein the front end portion and the rear end portion transition to the central portion along curving arcs in a helix direction from a portion adjacent to the inlet in a direction that becomes distant from the inlet, and the front end portion and the rear end portion are formed in parallel with a shaft of the washing tub, and
• wherein each protruding portion, of the plurality of protruding portions, includes a plurality of recessed portions formed in a length direction from the front end portion to the rear end portion of the protruding portion, and the plurality of recessed portions comprise an oval shape extended in the length direction from the front end portion to the rear end portion of the protruding portion.