The present invention provides a microfluidic device with a micro-pump system in which the production process is simplified and the device is further downsized. A microfluidic device 1 has a gas generation portion 3. The gas generation portion 3 has a substrate 10 and a gas generation layer 20. The substrate 10 has a first main surface 10a and a second main surface 10b. The substrate 10 has a micro-channel 14 with an opening at least on the first main surface 10a. The gas generation layer 20 is disposed on the first main surface 10a of the substrate 10 so as to cover an opening 14a. The gas generation layer 20 generates gas by receiving an external stimulus.
