A cassette which receives a substrate, and a substrate receiving system including a chamber which receives a cassette in which a substrate is loaded are provided. The cassette which receives a substrate includes: a plurality of slot supports stacked in a first direction; and a frame connected to the plurality of slot supports and extending in the first direction, wherein the plurality of slot supports and the frame are opened in an outward direction to receive the substrate, and are closed in an inward direction after the substrate is received.