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Multiple color selection techniques have been successful in identifyingquasars from wide-field broad-band imaging survey data. Among the quasars thathave been discovered so far, however, there is a redshift gap at $5 \lesssim{\rm z} \lesssim 5.7$ due to the limitations of filter sets in previousstudies. In this work, we present a new selection technique of high redshiftquasars using a sequence of medium-band filters: nine filters with centralwavelengths from 625 to 1025 nm and bandwidths of 50 nm. Photometry with thesemedium-bands traces the spectral energy distribution (SED) of a source, similarto spectroscopy with resolution R $\sim$ 15. By conducting medium-bandobservations of high redshift quasars at 4.7 $\leq$ z $\leq$ 6.0 and browndwarfs (the main contaminants in high redshift quasar selection) using the SEDcamera for QUasars in EArly uNiverse (SQUEAN) on the 2.1-m telescope at theMcDonald Observatory, we show that these medium-band filters are superior tomulti-color broad-band color section in separating high redshift quasars frombrown dwarfs. In addition, we show that redshifts of high redshift quasars canbe determined to an accuracy of $\Delta{\rm z}/(1+{\rm z}) = 0.002$ -- $0.026$.The selection technique can be extended to z $\sim$ 7, suggesting that themedium-band observation can be powerful in identifying quasars even at there-ionization epoch.

The Infrared Medium-Deep Survey. V. A New Selection Strategy for Quasars at z > 5 based on Medium-Band Observation with SQUEAN