A Wireless Sensor Network (WSN), made of distributed autonomous nodes, is designed to monitor physical or environmental conditions. WSN have many application domains such as environment or health monitoring. Their de- sign must consider energy constraints, concurrency issues, node heterogeneity, while still meeting the quality requirements of life-critical applications. Formal verification helps to obtain WSN reliability, but usually requires a high expertise, which limits its adoption in industry. This paper presents VeriSensor, a domain specific modeling language (DSML) for WSN offering support for formal verification. VeriSensor is designed to be used by WSN experts. It can be automatically translated into a formal specifica- tion for model checking. We present the language and its translation into a formal model (we use Instantiable Transition Systems - ITS). A tool has been implemented. We used it to work on a case study, illustrating how several metrics and properties relevant to the domain can be evaluated.