This letter presents a 60 GHz on-off keying demodulator in a 0.13 mu m CMOS. The demodulator consists of a detector and a baseband amplifier and employs a gain-boosting technique for higher conversion gain. The measured conversion gain is 13.6 dB at -16 dBm of input power. The detector voltage responsivity is 2434 mV/mW, which is the highest value in a 60 GHz silicon-based demodulator. The demodulator consumes 14.7 mW, and the measured maximum data rate is 5 Gb/s. the energy per bit, which indicates energy efficiency, exhibits 2.94 pJ/b. To the best of our knowledge, this demodulator achieves the highest data rate and the lowest energy per bit of all published 60 GHz band OOK demodulators using silicon-based technology.