Infrared observations of the NGC 7538 region at wavelengths from 1 μm to 1 mm are presented and analysed with the aim of understanding both the large-scale structure of this region of current star formation and the properties of the individual compact objects within it. At far-infrared wavelengths (25–130 μm), emission is seen from the visible H II region, from the vicinity of the previously known maser sources and dust-embedded compact H II regions, and from a new region called NGC 7538(E). Coincident with NGC 7538(E) are a point-like 1–25 μm infrared source, NGC 7538-IRS9, which probably provides the power for the far-infrared emission, and an extended source of 2.2 μm emission which appears to be an infrared reflection nebula. NGC 7538-IRS9 strongly resembles the compact H II region NGC 7538-IRS1 in its infrared properties but shows no radio continuum emission. The compact H II regions, the maser sources and IRS9 are located within a dense molecular cloud at the edge of the optical H II region. This cloud, which has M∼9×10³M⊙, is detected in emission at 1 mm. The NGC 7538 region appears to contain examples of different stages in the formation of massive stars; it is suggested that the centre of star formation is moving systematically to the south-east in this region
