The North Ecliptic Pole (NEP) Wide survey covered about 5.4 deg 2 , a nearly circular area centered on the NEP, using nine passbands of InfraRed Camera (IRC). We present the photometric properties of the data sets, and the nature of the sources detected in this field. The number of detected sources varied according to the filter band: with about 109,000 sources in the NIR, about 20,000 sources in the MIR-S, and about 16,000 sources seen in the MIR-L channel. The 5σ detection limits are about 21 mag in the NIR and 19.5 - 18.5 mag in the MIR bands in terms of the AB magnitude. 50% completeness levels are about 19.8 mag at 3 μm , 18.6 mag at 9 μm , and 18 mag at 18 μm band (in AB magnitude), respectively. In order to validate the detected sources, all of them are confirmed by matching tests with those in other bands. The 'star-like' sources, defined by the high stellarity and magnitude cut from the optical ancillary data, appear statistically to have a high probability of being stars. The nature of the various types of extragalactic sources in this field are discussed using the color-color diagrams of the NIR and MIR bands with the redshift tracks of galaxies providing useful guidelines.

ABSTRACT
1. INTRODUCTION
2. DATA REDUCTION
    2.1. Pre-Processing
    2.2. Image Correction
3. SOURCE DETECTION AND DATA PROPERTIES
4. NATURE OF THE SOURCES
5. SUMMARY
REFERENCES

• HYUNG MOK LEE(Department of Physics and Astronomy, Seoul National University)
• SEONG JIN KIM(Department of Physics and Astronomy, Seoul National University)
• NEP-WIDE TEAM(Department of Physics and Astronomy, Seoul National University)