An indoor unit of an air-conditioning apparatus, comprising: a front panel arranged on a front side of an indoor unit body and having a flat shaped front surface; and the front panel including: a recess formed to be recessed from the front side to a back side in a center of the front panel in an up-and-down direction in front view, and extending from a right side of a left end portion of the front panel to a left side of a right end portion of the front panel; an air inlet formed below the recess; a left-hand recess side portion positioned on a left side of the recess of the front panel in front view; and a right-hand recess side portion positioned on a right side of the recess of the front panel in front view, characterized in that the indoor unit further comprises a design cover mounted on a front side of the front panel wherein said design cover includes: an upper design cover configured to cover a region extending from an upper end portion of the recess to an upper end portion of the front panel and extending from a left end portion to a right end portion of the front panel in front view; and a lower design cover formed separately from the upper design cover and configured to cover a region extending from a lower end portion of the recess to a lower end portion of the front panel and extending from the left end portion to the right end portion of the front panel in front view, the left-hand recess side portion being flat and flush with flat surfaces above and below the left-hand recess side portion, the right-hand recess side portion being flat and flush with flat surfaces above and below the right-hand recess side portion. a front panel arranged on a front side of an indoor unit body and having a flat shaped front surface; and the front panel including: a recess formed to be recessed from the front side to a back side in a center of the front panel in an up-and-down direction in front view, and extending from a right side of a left end portion of the front panel to a left side of a right end portion of the front panel; an air inlet formed below the recess; a left-hand recess side portion positioned on a left side of the recess of the front panel in front view; and a right-hand recess side portion positioned on a right side of the recess of the front panel in front view, a recess formed to be recessed from the front side to a back side in a center of the front panel in an up-and-down direction in front view, and extending from a right side of a left end portion of the front panel to a left side of a right end portion of the front panel; an air inlet formed below the recess; a left-hand recess side portion positioned on a left side of the recess of the front panel in front view; and a right-hand recess side portion positioned on a right side of the recess of the front panel in front view, characterized in that the indoor unit further comprises a design cover mounted on a front side of the front panel wherein said design cover includes: an upper design cover configured to cover a region extending from an upper end portion of the recess to an upper end portion of the front panel and extending from a left end portion to a right end portion of the front panel in front view; and a lower design cover formed separately from the upper design cover and configured to cover a region extending from a lower end portion of the recess to a lower end portion of the front panel and extending from the left end portion to the right end portion of the front panel in front view, an upper design cover configured to cover a region extending from an upper end portion of the recess to an upper end portion of the front panel and extending from a left end portion to a right end portion of the front panel in front view; and a lower design cover formed separately from the upper design cover and configured to cover a region extending from a lower end portion of the recess to a lower end portion of the front panel and extending from the left end portion to the right end portion of the front panel in front view, the left-hand recess side portion being flat and flush with flat surfaces above and below the left-hand recess side portion, the right-hand recess side portion being flat and flush with flat surfaces above and below the right-hand recess side portion.