This paper describes the characteristics of a poly 3C-SiC micro heater which was fabricated on AlN(0.1 $mu$m)/3C-SiC(1.0 $mu$m) suspended membranes by surface micro-machining technology. The 3C-SiC and AlN thin films which have wide energy band gap and very low lattice mismatch were used sensors for high temperature and voltage environments. The 3C-SiC thin film was used as micro heaters and temperature sensor materials simultaneously. The implemented 3CSiC RTD(resistance of temperature detector) and the power consumption of micro heaters were measured and calculated. The TCR(thermal coefficient of the resistance) of 3C-SiC RTD is about -5200 ppm/$^{circ}C$ within a temperature range from 25 $^{circ}C$ to 50 $^{circ}C$ and -1040 ppm/$^{circ}C$ at 500 $^{circ}C$. The micro heater generates the heat about 500 $^{circ}C$ at 10.3 mW. Moreover, durability of 3C-SiC micro heaters in high voltages is better than Pt micro heaters. A thermal distribution measured and simulated by IR thermovision and COMSOL is uniform on the membrane surface.