  Imaging polarimetry of the 0.85mm continuum emission in the NGC 7538 region,
obtained with the SCUBA Polarimeter, is presented. The polarization map is
interpreted in terms of thermal radiation by magnetically aligned dust grains.
Two prominent cores associated with IRS 1 and IRS 11, IRS 1(SMM) and IRS
11(SMM), are found in the surface brightness map. Although these cores look
similar in surface brightness, their polarization shows striking differences.
In IRS 11(SMM), the polarization vectors are extremely well ordered, and the
degrees of polarization are quite high with an average of ~3.9 %. In IRS
1(SMM), on the other hand, the directions of polarization vectors are locally
disturbed, and the degrees of polarization are much lower than those of IRS
11(SMM). These differences suggest that small scale fluctuations of the
magnetic field are more prominent in IRS 1(SMM). This can be interpreted in
terms of the difference in evolutionary stage of the cores. Inside IRS 1(SMM),
which seems to be at a later evolutionary stage than IRS 11(SMM), substructures
such as subclumps or a cluster of infrared sources have already formed. Small
scale fluctuations in the magnetic field could have developed during the
formation of these substructures. The distribution of magnetic field directions
derived from our polarization map agrees well with those of molecular outflows
associated with IRS 1(SMM) and IRS 11(SMM). Comparisons of energy densities
between the magnetic field and the outflows show that the magnetic field
probably plays an important role in guiding the directions of the outflows.
