This invention relates to a new portable device with no solid frame, which makes it possible to carry out instrumented indentation of a material to deduct its mechanical properties. Continuous or instrumented indentation consists in measuring the force and displacement when an indenter is pushed into the tested material. The device is made up of a sleeve with a reduced volume and its lower base, which may be of variable shapes adapted to that of the material to test, a piston sliding in the sleeve, the displacement of which is controlled by the hand of a user, a manipulating arm, a mechanical column or a robot, an elastic ring or a spring limiting the displacement of the piston, three displacement sensors arranged in an equilateral triangle around a single-piece indenter having any shape, and a force sensor that makes it possible to measure the change in the force depending on the depression made by the indenter in the tested material.