An indoor unit for an air-conditioning apparatus, comprising: a casing having an air inlet formed in an upper part of the casing and an air outlet formed below a front part of the casing, wherein a side close to the front part is referred to as front side of the casing, the casing accommodating therein a heat exchanger and a fan; at least one horizontal airflow-direction louver mounted pivotally inside the air outlet to guide airflow through the air outlet in a horizontally changeable manner; at least one vertical airflow-direction louver (2, 3, 4, 5) mounted to cover the air outlet in a closed position and to guide airflow through the air outlet in a vertically changeable manner; an infrared sensor projecting downward from the casing at a position in a horizontal end portion of the casing and in front of the air outlet, that is at a position closer to the front part than a position of the air outlet of the casing; at least one airflow blocking portion (20, 30) located behind the infrared sensor, i.e. being provided close to a back of the casing with respect to the infrared sensor, the at least one airflow blocking portion (20, 30) having a side wall (21, 31) on or beside one edge of the air outlet; the side wall (21, 31) located closer to a center of the air outlet in the horizontal direction than the infrared sensor; characterized in that the indoor unit for an air-conditioning apparatus further comprises an airflow deflecting wall (22, 32) provided to the side wall (21, 31) of the at least one airflow blocking portion (20, 30), the airflow deflecting wall (22, 32) being configured to deflect, away from the infrared sensor, airflow directed to the side wall (21, 31) at least by the horizontal airflow-direction louver. a casing having an air inlet formed in an upper part of the casing and an air outlet formed below a front part of the casing, wherein a side close to the front part is referred to as front side of the casing, the casing accommodating therein a heat exchanger and a fan; at least one horizontal airflow-direction louver mounted pivotally inside the air outlet to guide airflow through the air outlet in a horizontally changeable manner; at least one vertical airflow-direction louver (2, 3, 4, 5) mounted to cover the air outlet in a closed position and to guide airflow through the air outlet in a vertically changeable manner; an infrared sensor projecting downward from the casing at a position in a horizontal end portion of the casing and in front of the air outlet, that is at a position closer to the front part than a position of the air outlet of the casing; at least one airflow blocking portion (20, 30) located behind the infrared sensor, i.e. being provided close to a back of the casing with respect to the infrared sensor, the at least one airflow blocking portion (20, 30) having a side wall (21, 31) on or beside one edge of the air outlet; the side wall (21, 31) located closer to a center of the air outlet in the horizontal direction than the infrared sensor; characterized in that the indoor unit for an air-conditioning apparatus further comprises an airflow deflecting wall (22, 32) provided to the side wall (21, 31) of the at least one airflow blocking portion (20, 30), the airflow deflecting wall (22, 32) being configured to deflect, away from the infrared sensor, airflow directed to the side wall (21, 31) at least by the horizontal airflow-direction louver.