Provided is an indoor unit for an air-conditioning apparatus, which prevents adhesion of dew condensation water to up-and-down airflow direction louvers while directing blowing air to an intended direction. The indoor unit for an air-conditioning apparatus according to the present invention, includes: a casing, which is to be mounted to a wall surface in a room at a back surface side of the casing; an air inlet; an air outlet; an indoor heat exchanger and an indoor fan, which are arranged in an air passage continuous from the air inlet to the air outlet; an up-and-down airflow direction louver, which is arranged in the air outlet to be able to turn, forms an air outlet passage for the blowing air at a portion below the air outlet, and is configured to change a direction of the blowing air in an up-and-down direction; and an up-and-down airflow direction auxiliary louver, which is positioned on a front surface side of the casing relative to the up-and-down airflow direction louver in the air outlet, forms the air outlet passage, and is configured to change the direction of the blowing air in the up-and-down direction. The up-and-down airflow direction louver includes: an upstream guide surface, which is configured to guide a flow of the blowing air; and a downstream guide surface, which is positioned on the air outlet passage side and is arranged on a downstream side of the air outlet passage and on an outer side of the air outlet passage relative to the upstream guide surface, and is configured to guide the flow of the blowing air. The up-and-down airflow direction auxiliary louver includes an upstream end portion, the upstream end portion being positioned on an inner side of the air outlet passage relative to the downstream guide surface and being positioned on the upstream side relative to a downstream guide surface distal end portion of the downstream guide surface, which is an end portion of the downstream guide surface on the downstream side of the air outlet passage.