Abstract: A micropump is disclosed including an input port, an output port, a fluid channel space located therebetween, a first oscillating member for opening or closing between the fluid channel space and the input port, a second oscillating member for opening or closing between the fluid channel space and the output port, and at least one third oscillating member for reducing/enlarging the volume of the fluid channel space. The micropump is provided with pressure correcting means which applies a pressure, substantially equal to a fluid pressure at the input port, to a space located outside the fluid channel space and in which the first oscillating member oscillates.