To provide a micropump device having good controllability over the amount of gas generated from the gas generating material and thus the amount of liquid fed by the micropump. The micropump device includes a micropump 10 and a controller 50. The micropump 10 includes: a microchannel 22 serving as a channel for liquid; a gas generating material 34 generating a gas upon exposure to light and supplying the gas to the microchannel 22; and a light source 42 for irradiating the gas generating material 34 with light 44. The controller 50 supplies to the light source 42 a control pulse signal CS that causes the light source 42 to blink on and off in a binary manner by repeating a pulse train pattern composed of a fixed number of bits each capable of having two states, one of which is a first level allowing the light source 42 to be turned on and the other of which is a second level allowing the light source 42 to be turned off.