The invention relates to a filling machine for producing sausages and a method for monitoring the state of fouling of a collection container and/or a channel which is in communication with the collection container of such a filling machine, where the filling machine comprises a vane cell pump for delivering pasty mass, a vacuum pump for generating negative pressure of the vane cell pump, where the vane cell pump is via the collection container for the pasty mass that is dragged along in communication with the vacuum pump. The filling machine further comprises an inspection opening that is via a channel in communication with the collection container for inspecting the channel and/or the collection container.