The device is used to test the stability of an apparatus that requires a surface in order to work, and confirm to the IEC60335-1 clause 20.1. The device consists of a surface and an angle adjusting device, with angles 0~15° adjustable. The appliance is placed in any normal position of use on a plane inclined at an angle of 10° to the horizontal, the supply cord resting on the inclined plane in the most unfavourable position. However, if part of an appliance comes into contact with the horizontal supporting surface when the appliance is tilted through an angle of 10°, the appliance is placed on a horizontal support and tilted in the most unfavourable direction through an angle of 10°. Appliances provided with doors are tested with the doors open or closed, whichever is the more unfavourable. Appliances intended to be filled with liquid by the user in normal use are tested empty or filled with the most unfavourable quantity of water up to the capacity indicated in the instructions. The appliance shall not overturn.