Disclosed herein are a steam generator (600), a laundry machine, and a control method of the laundry machine. The steam generator (600) includes a steam generation unit (610) having a water inlet port (612) formed at one side thereof, an outlet port (613) formed at the other side thereof, and a flow channel (611) connected between the water inlet port (612) and the outlet port (613); and a heater (640) for heating water being supplied through the water inlet port (612) to generate steam. The laundry machine includes a machine case (100) forming the external appearance thereof, a drum (400) rotatably mounted in the machine case (100), and a steam generator (600) having a steam generation unit (610) with a flow channel (611) connected between a water inlet port (612) formed at one side thereof and an outlet port (613) formed at the other side thereof, and a heater (640) for heating water being supplied through the water inlet port (612) to generate steam. The control method includes a steam supply step of heating water being supplied through the water inlet port (612) of the steam generation unit (610) by the heater (640) to generate steam and supplying the generated steam to the drum (400).