An air conditioner indoor unit allowing removal for washing. An air duct structure (4) comprises an upper air duct housing (31) and a lower air duct housing (32); the upper air duct housing (31) is connected to a base (2) and defines an upper air duct portion (33) together with the base (2); the lower air duct housing (32) is removably connected to the upper air duct housing (31), and the upper air duct portion (33) and a lower air duct portion (326) are connected to form an air duct curvedly extending from the top to the front bottom; a fan (5) is disposed in the air duct, and the fan (5) is mounted on the upper air duct housing (31).