The design and construction of a charge-coupled device (CCD) imaging system optimized for the detection of low surface brightness objects is discussed in detail. In particular, we describe the design of the Dewar and the CCD electronics, as well as the choice of CCD operating voltages, clock timings, and operating temperature. In addition, we discuss the measurement of readout and spatial noise for an RCA SID536l2 thinned CCD (320 by 512 pixels). For this chip, we find a readout noise of 64 electrons and obtain a well depth in excess of 350000 electrons with essentially no blemishes or bleeding of charge on bright star images. The threshold level for trailing of charge is 300 electrons in the center of the chip and is essentially zero in the corner of the chip which is read out first. On broadband exposures, fringing from night-sky lines is typically seen only in the infrared (∼ 8700 Å) at about 2% of the night- sky level. Our twilight flat-field exposures taken on different nights are consistent with each other at a level varying from one part in 100000 to a few parts in 10000 on the large scale, and the zero level is stable to ± 10 electrons over a night. The system is linear over its entire range, and we can currently do photometry to better than 0.8% using standard stars.