The invention relates to a method for evaluating the mechanical performances of a switchgear device comprising at least one pole. Each pole comprises: a pair of contacts (12, 14); a support arm (16) for a first contact (14); a mechanism (22) for driving the support arm (16) comprising a rotary poles shaft (20) and energy accumulation means capable of driving a movement of the said arm in order to place the contacts (12, 14) in an open position. The method consists in: measuring the angle of rotation (θ) of the poles shaft (20) over a period of opening the contacts (12, 14); retrieving from the measurements at least one specific value; comparing the said specific value with specific initial operational specifications of the switchgear device; diagnosing the mechanical wear performances of the drive mechanism (22) as a function of a comparative state between the specific values obtained and those of the operational specifications.