A method of controlling a laundry treatment apparatus that includes a cabinet (2, 110, 210) including a first opening and a second opening, a first cabinet door that is coupled to the cabinet (2, 110, 210) and that is configured to open or close the first opening, a second cabinet door that is coupled to the cabinet (2, 110, 210) and that is configured to open or close the second opening, a first washing apparatus that is located in the cabinet and that is configured to treat laundry introduced into an interior area of the first washing apparatus through the first cabinet door in a first direction, and a second washing apparatus that is configured to treat laundry introduced into an interior area of the second washing apparatus through the second cabinet door in a second direction, the second washing apparatus including a tub that is accessible through the second opening in a state in which the second cabinet door is opened, that is configured to store water, and that includes a tub opening at a top of the tub, a tub cover that is coupled to the tub, that covers the tub opening, and that includes an introduction port through which laundry is introduced into the interior area of the second washing apparatus, a tub door that is coupled to the tub cover, that is configured to open or close the introduction port, and that is independently operated of the second cabinet door, a drum that is located in the tub and that is configured to rotate about a shaft, the shaft extending in the second direction, and a controller that is configured to control operations of the second washing apparatus, a spray unit for spraying water introduced through a supply port toward a bottom inner surface of the drum, and wherein the method comprises: sequentially performing, with the second washing apparatus, a washing cycle, a rinsing cycle, and a spin-drying cycle, determining whether bubbles have been generated in the tub during the washing cycle, sequentially performing, during the rinsing cycle, draining washing water from the tub, intermittently spinning the drum to dry laundry using centrifugal force generated by rotation of the drum, supplying wash water in the tub, and rinsing laundry, wherein, if bubble generation has been determined in the washing cycle, at least one operation directed to reducing bubbles by spraying water with the spray unit toward a bottom inner surface of the drum after the step of draining washing water and before the step of intermittently spinning the drum in the rinsing cycle is performed. a tub that is accessible through the second opening in a state in which the second cabinet door is opened, that is configured to store water, and that includes a tub opening at a top of the tub, a tub cover that is coupled to the tub, that covers the tub opening, and that includes an introduction port through which laundry is introduced into the interior area of the second washing apparatus, a tub door that is coupled to the tub cover, that is configured to open or close the introduction port, and that is independently operated of the second cabinet door, a drum that is located in the tub and that is configured to rotate about a shaft, the shaft extending in the second direction, and a controller that is configured to control operations of the second washing apparatus, a spray unit for spraying water introduced through a supply port toward a bottom inner surface of the drum, and sequentially performing, with the second washing apparatus, a washing cycle, a rinsing cycle, and a spin-drying cycle, determining whether bubbles have been generated in the tub during the washing cycle, sequentially performing, during the rinsing cycle, draining washing water from the tub, intermittently spinning the drum to dry laundry using centrifugal force generated by rotation of the drum, supplying wash water in the tub, and rinsing laundry, wherein, if bubble generation has been determined in the washing cycle, at least one operation directed to reducing bubbles by spraying water with the spray unit toward a bottom inner surface of the drum after the step of draining washing water and before the step of intermittently spinning the drum in the rinsing cycle is performed.