A clamping device for holding a container in a container treatment device, for example for holding a beverage container at a neck portion, comprising two clamping arms with a holding portion for holding the container to be held, and a control cam which is pivotable about a control cam pivot axis, wherein the clamping arms and the control cam are coupled via a coupling mechanism so that a pivoting of the control cam about its control cam pivot axis causes a pivoting of the clamping arms relative to one another, and the coupling mechanism comprises at least one pair of a slotted groove and a control bolt guided in the slotted groove for transmitting movements of the control cam to the clamping arms.