Proposed is a universal mechanical tester for measuring friction and wear characteristics of materials. The tester allows performing multiple test protocols with a single machine. The tester consists of a frame that supports a carriage moveable in a vertical direction, a force sensor assembly attached to the carriage, a positioning stage with a slide and a platform, and a plurality of modular sample stages interchangeably installable on the platform for executing linear and rotary motions of the lower sample relative to the upper sample in various directions and planes. The tester is provided with a set of electronic identification devices for identifying a modular sample stage installed on the platform and the force sensor assembly attached to the carriage.