A laundry treatment apparatus including a cabinet defining an appearance thereof, a tub disposed in the cabinet, a drum rotatably disposed in the tub, and an air supply unit configured to heat and circulate air in the tub, the air supply unit comprising: a fan duct coupled to an air collection port provided at the tub so as to collect the air in the tub and having outflow ports (213, 217) through which air is discharged; a heating duct fixed to an upper portion of the tub so as to heat air supplied from the fan duct and having inflow ports (223, 228) connected to the outflow ports (213, 217) and an air supply port for supplying the heated air; a supply duct connected to the air supply port so as to supply air in a forward direction of the tub; couplers (210a, 220a, 210b, 220b) located at the heating duct and the fan duct to couple the heating duct and the fan duct such that the inflow ports (223, 228) and the outflow ports (213, 217) communicate with each other; and a heating duct coupler provided at the supply duct and a supply duct coupler provided at the heating duct to connect the supply duct and the air supply port, characterised in that the couplers (210a, 220a, 210b, 220b) comprise: a first rotatable coupler, which is provided at one side of the outflow port (213, 217) and has a flat surface parallel to a direction in which the fan duct is coupled; and a second rotatable coupler, which is provided at one side of the inflow port (223, 228) and has a flat surface parallel to a direction in which the fan duct is coupled and to which the first rotatable coupler is rotatably coupled, and a first fixing coupler, which is provided at a remaining side of the outflow port (213, 217) and has a flat surface parallel to the outflow port (213, 217); and a second fixing coupler, which has a flat surface parallel to the inflow port (223, 228) and to which the first fixing coupler is fixed such that the fan duct is rotatable relative to the heating duct. a fan duct coupled to an air collection port provided at the tub so as to collect the air in the tub and having outflow ports (213, 217) through which air is discharged; a heating duct fixed to an upper portion of the tub so as to heat air supplied from the fan duct and having inflow ports (223, 228) connected to the outflow ports (213, 217) and an air supply port for supplying the heated air; a supply duct connected to the air supply port so as to supply air in a forward direction of the tub; couplers (210a, 220a, 210b, 220b) located at the heating duct and the fan duct to couple the heating duct and the fan duct such that the inflow ports (223, 228) and the outflow ports (213, 217) communicate with each other; and a heating duct coupler provided at the supply duct and a supply duct coupler provided at the heating duct to connect the supply duct and the air supply port, characterised in that the couplers (210a, 220a, 210b, 220b) comprise: a first rotatable coupler, which is provided at one side of the outflow port (213, 217) and has a flat surface parallel to a direction in which the fan duct is coupled; and a second rotatable coupler, which is provided at one side of the inflow port (223, 228) and has a flat surface parallel to a direction in which the fan duct is coupled and to which the first rotatable coupler is rotatably coupled, and a first fixing coupler, which is provided at a remaining side of the outflow port (213, 217) and has a flat surface parallel to the outflow port (213, 217); and a second fixing coupler, which has a flat surface parallel to the inflow port (223, 228) and to which the first fixing coupler is fixed such that the fan duct is rotatable relative to the heating duct. a first rotatable coupler, which is provided at one side of the outflow port (213, 217) and has a flat surface parallel to a direction in which the fan duct is coupled; and a second rotatable coupler, which is provided at one side of the inflow port (223, 228) and has a flat surface parallel to a direction in which the fan duct is coupled and to which the first rotatable coupler is rotatably coupled, and a first fixing coupler, which is provided at a remaining side of the outflow port (213, 217) and has a flat surface parallel to the outflow port (213, 217); and a second fixing coupler, which has a flat surface parallel to the inflow port (223, 228) and to which the first fixing coupler is fixed such that the fan duct is rotatable relative to the heating duct.