  Galaxy counts in the K band, (J-K)-colors, and apparent size distributions of
faint galaxies in the Subaru Deep Field (SDF) down to K~24.5 were studied in
detail. Special attention has been paid to take into account various selection
effects including the cosmological dimming of surface brightness, to avoid any
systematic bias which may be the origin of controversy in previously published
results. We also tried to be very careful about systematic model uncertainties;
we present a comprehensive surveys of these systematic uncertainties and
dependence on various parameters. We found that the pure luminosity evolution
(PLE) model is well consistent with all the SDF data down to K~22.5, without
any evidence for number or size evolution in a low-density, Lambda-dominated
flat universe which is now favored by various cosmological observations. If the
popular Lambda-dominated universe is taken for granted, our result then gives a
strong constraint on the number evolution of giant elliptical or early-type
galaxies to z~1-2 which must be met by any models in the hierarchically
clustering universe, since such galaxies are the dominant population in this
magnitude range (K<~22.5). In the fainter magnitude range of K>~22.5, we found
a slight excess of observed counts over the prediction of the PLE model when
elliptical galaxies are treated as a single population. We suggest that this
discrepancy reflects some number evolution of dwarf galaxies and/or the
distinct populations of giant and dwarf elliptical galaxies which have been
known for local elliptical galaxies.
