An apparatus for the condition checking of a screen cloth in a vibrating screen for drilling fluid, comprising a pump for drawing a drilling fluid sample from the bottom tray of the vibrating screen into the apparatus, a filter for filtering the drilling fluid sample, and a pressure gauge for measuring the pressure difference across the filter. A method for the condition checking of a screen cloth in a vibrating screen, comprising drawing a drilling fluid sample from the bottom tray of the vibrating screen, filtering the drilling fluid sample through a filter, and measuring the pressure difference across the filter.