A hermetic compressor is provided that may include a casing having an inner space, an orbiting scroll provided in the inner space, a non-orbiting scroll engaged with the orbiting scroll to form compression chambers, a high/low pressure dividing plate that divides the inner space into high and low pressure portions, and an overheat preventing unit coupled to a surface of the dividing plate at the high pressure portion, the overheat preventing unit having a communication hole formed through the dividing plate to communicate the high and low pressure portions, and having a valve spaced from the dividing plate by a predetermined interval to selectively open/close the communication hole according to a temperature variation of the high pressure portion, whereby transfer of a refrigerant temperature of the low pressure portion to the overheat preventing unit through the dividing plate may be prevented, and the compressor may be quickly stopped upon being overheated, thereby being protected from damage.