A process and a device for separating and exhausting gas bubbles from a flowing liquid, especially in a microfluidic system, are proposed. Radial deflection of the liquid, a preferably annular deaeration chamber from which gas can escape through gas separation material, and a following discharge filter are characteristic. The discharge filter is made of a hydrophilic material which forms pores or small channels. Optionally, there is an inlet filter of the corresponding material upstream of the deaeration chamber.