An indoor unit for an air conditioner, comprising: a housing provided with an air inlet, a first air outlet, and a second air outlet, an air duct flow path communicating the air inlet with the first air outlet and an air duct flow path communicating the air inlet with the second air outlet being provided in the housing; a fan assembly provided in the housing to guide air to circulate in the air duct flow paths; a first driving mechanism and a first door, wherein the first driving mechanism is provided in the housing and is connected to the first door to drive the first door to move, so that the first door has an open state and a closed state; when the first driving mechanism drives the first door to move outwards relative to the housing to a set position, the first door is switched to the open state; in the open state, the first door opens the first air outlet; in the closed state, the first door cooperates with the housing to close the first air outlet; a second door and a second driving mechanism, wherein the second driving mechanism is connected to the second door to drive the second door to slide relative to the housing to open or close the second air outlet; the first door comprising: a flow guiding member connected to the first driving mechanism to be driven to move by the first driving mechanism, so that an outer peripheral wall of the flow guiding member guides air flow when the first door is in the open state; and a sealing member connected to the flow guiding member, so that the sealing member cooperates with the housing to close the first air outlet when the first door is in the closed state; characterised in that: a vertical sectional area of the flow guiding member increases gradually along a direction from the air inlet to the first air outlet; and the second driving mechanism drives the second door to slide in a vertical direction. a housing provided with an air inlet, a first air outlet, and a second air outlet, an air duct flow path communicating the air inlet with the first air outlet and an air duct flow path communicating the air inlet with the second air outlet being provided in the housing; a fan assembly provided in the housing to guide air to circulate in the air duct flow paths; a first driving mechanism and a first door, wherein the first driving mechanism is provided in the housing and is connected to the first door to drive the first door to move, so that the first door has an open state and a closed state; when the first driving mechanism drives the first door to move outwards relative to the housing to a set position, the first door is switched to the open state; in the open state, the first door opens the first air outlet; in the closed state, the first door cooperates with the housing to close the first air outlet; a second door and a second driving mechanism, wherein the second driving mechanism is connected to the second door to drive the second door to slide relative to the housing to open or close the second air outlet; the first door comprising: a flow guiding member connected to the first driving mechanism to be driven to move by the first driving mechanism, so that an outer peripheral wall of the flow guiding member guides air flow when the first door is in the open state; and a sealing member connected to the flow guiding member, so that the sealing member cooperates with the housing to close the first air outlet when the first door is in the closed state; characterised in that: a vertical sectional area of the flow guiding member increases gradually along a direction from the air inlet to the first air outlet; and the second driving mechanism drives the second door to slide in a vertical direction. a flow guiding member connected to the first driving mechanism to be driven to move by the first driving mechanism, so that an outer peripheral wall of the flow guiding member guides air flow when the first door is in the open state; and a sealing member connected to the flow guiding member, so that the sealing member cooperates with the housing to close the first air outlet when the first door is in the closed state; characterised in that: a vertical sectional area of the flow guiding member increases gradually along a direction from the air inlet to the first air outlet; and the second driving mechanism drives the second door to slide in a vertical direction. a vertical sectional area of the flow guiding member increases gradually along a direction from the air inlet to the first air outlet; and the second driving mechanism drives the second door to slide in a vertical direction.