Considerable effort has gone into the study of the failure mechanisms and reliability of micro-electro-mechanical-systems (MEMS) to extend its use to critical areas. In this paper a prototype of SOI microrelays is evaluated for space applications. The MEMS devices are subjected to uniform proton beam of 10MeV, while its response is monitored by electrical characteristics for successive irradiation pulses. Although the system shows a significant increase of positive trapped charge, it has not been found any limitation on the functionality based in the main parameters such as the actuation voltage, the leakage currents, and conduction mechanism of the switch.