Silicon oxynitride (SiON)- technology has been widely accepted for realizing integrated optical devices for application in optical telecommunication. Some of the severe requirements put in this field to devices and hence to technology are more relaxed in sensing applications, but other ones pop up in this area. These differences are explained from the general requirements put on the performance of integrated optical sensors performance and they are analyzed with respect to their consequences for applying SiON technology. Data about the technology are given. Application of the technology is illustrated on some chemo-optical sensors, a Mach-Zehnder interferometer, a polarimeter and a bend sensor, which have been developed in the MESA+-institute.