We present two methods for creating polymeric microfluidic devices integrated with electrospray tips for use with mass spectrometry. SU-8 was used to create microfluidic channels and electrospray tips. The planar electrospray tips were located at the end of microfluidic channels and were formed using standard photolithography. The encapsulation of the microfluidic channels was accomplished by using thermal and press bonding between two SU-8 layers, or by employing a sacrificial layer removal technique. We successfully coupled these microfluidic chips to a mass spectrometer. In particular, the microfluidic device fabricated with the sacrificial layer removal method shows satisfactory electrospray stability.