1. A touch detection circuit comprising: a map generation section configured to compare a touch signal corresponding to a proximity state of an external proximity object with each of a plurality of thresholds to generate a plurality of pieces of map data each showing touch regions; a labeling section configured to selectively perform labeling on the touch regions in the plurality of pieces of map data, based on inclusive relationship of the touch regions between the plurality of pieces of map data; and a detection section configured to perform touch detection based on processing results by the labeling section, wherein the labeling section is configured to generate a first label set indicating correspondence between the touch regions and labels by providing the labels to the respective touch regions in each of the map data, and sequentially selecting two pieces of map data corresponding to two thresholds adjacent to each other, from the plurality of pieces of map data, and replacing the labels based on the inclusive relationship of the touch regions in the selected two pieces of map data.