Design, characterization and system implementation of a temperature regulator for methanol fed fuel microreactor for hydrogen production in fuel cells applications are presented. The regulator was designed around Texas Instruments MSP430 microcontroller, which acquires temperature in the microreactor and sets the output power of the heater in order to maintain the required temperature in the microevaporator stage of the microreactor. It also serves as a user interface device for controlling the operating conditions in the microreactor. The temperature is sampled with an integrated platinum temperature dependent resistor. Its output is amplified and applied to the internal analog to digital converter of the microcontroller. The temperature control is achieved by ON-OFF regulation principle with an adjustable hysteresis. The heater actuation circuit comprises a boost converter, controlled by pulse width modulated signal from the microcontroller. The output of the boost converter is applied to the platinum (Pt) heater in the microreactor evaporation stage. The regulator was tested with a microreactor evaporation stage using different Pt heaters and temperature sensors, designed and manufactured in LMSE and heater start-up time, power and regulation ripple were measured.