A mini excavator, machine that could be often seen in our surroundings, can become a very complex structure. Throughout the entire history of development, it was constantly improved because of its practicality and usefulness in work. With the aim of increasing the types of work it can do, numerous options were added that made the relatively small machine multi- functional. In order to fit all this within the limits of mass and dimensions, the need of optimization individual components arose. The hydraulic system forms the basis of the machine, and we try to get the most out of it in order to reduce mass and increase utility. The system is also adapted to the targeted appearance of the machine in order to maintain all its functions and required values in terms of dimensions and power. After market research and considering existing products mini excavator concept has been made, according to which the components of the upper and lower structure, i.e. superstructure and undercarriage, were arranged. The overall design followed the already existing look of machines from other manufacturers in order to keep it within the dimensions. Based on the required performance, the calculation of the components of the working device was carried out for the case of static loading under the action of a critical force, the breakout force. All built-in components have been selected at the level of the layout proposal and their shape. Each part is described separately and the appearance of the complete machine, made in a 3D CAD model, is shown as the final result of the entire work.