A method for controlling the through-flow cross-section of a gas valve is described. The gas valve comprises a valve body in which a flow channel is provided, a valve element which can be displaced therein between a closed position and an opened position, an armature, a coil, a spring and a control circuit. For opening the flow channel, the control circuit excites the coil with a pulse width-modulated current, the pulse duty factor of which, starting from a starting value, is increased until the armature starts moving out of the closed position against the effect of the spring. Then, the control circuit reduces the pulse duty factor before the valve element has reached the opened position. The control circuit then sets the pulse duty factor at a predefined holding value with which the valve element is held in the opened position.