  Near-infrared surveys of high-mass star-forming regions start to shed light
onto their stellar content. A particular class of objects found in these
regions, the so-called massive Young Stellar Objects (YSOs) are surrounded by
dense circumstellar material. Several near- and mid-infrared diagnostic tools
are used to infer the physical characteristics and geometry of this
circumstellar matter. Near-infrared hydrogen emission lines provide evidence
for a disk-wind. The profiles of the first overtone of the CO band-heads,
originating in the inner 10 AU from the central star, are well fitted assuming
a keplerian rotating disk. The mid-infrared spectral energy distribution
requires the presence of a more extended envelope containing dust at a
temperature of about 200 K. CRIRES observations of CO fundamental absorption
lines confirm the presence of a cold envelope. We discuss the evolutionary
status of these objects.
