Thermocouples are very sensitive, requiring a good amplifier with a cold-compensation reference. The MAX31855K does everything for you, and can be easily interfaced with any microcontroller, even one without an analog input. This breakout board has the chip itself, a 3.3V regulator with 10uF bypass capacitors and level shifting circuit, all assembled and tested. Comes with a 2 pin terminal block (for connecting to the thermocouple) and pin header (to plug into any breadboard or perfboard).

Features:

Works with any K type thermocouple
Will not work with any other kind of thermocouple other than K type
-200°C to 1350°C output in 0.25 degree increments - note that K thermocouples have about ±2°C to ±6°C accuracy
Internal temperature reading
3.3 to 5v power supply and logic level compliant!
SPI data output requires any 3 digital I/O pins.

Dimensions:

Length: 20mm/0.8in
Width: 20mm/0.8in
Height: 3.28mm/0.12in 
Weight: 1.33g/0.05oz