The topological optimization is based on the distribution of material in a space, in a way that it will waste the less amount of this to yield a particular piece of a machine, a car, etc. By defining a domain chosen by the draftsman the challenge now is to find what s the best distribution of material trying to solve the problem of minimization. The objective of this work is, by the help of MatLab codes, and, jointly with an interface, make projects of mechanical pieces that will consume the lesser amount of material, generating the fewest waste in his fabrication. To do this, it will be presented parameters, that will be explained in this work, to be defined by the user and, by doing this, we will get the best results. The method used to make all the calculations will be based on the thesis of Bendsoe and Kikuchi (1988), that is, it will be considered an equation constitutive homogenised that will depend only on the relative density of the material. Also to the finite elements routine, it will be considered approaches of squares with four nodes. In the end of this work it will be presented an analyses comparing different kinds of mechanical pieces before and after the code of optimization, jointly with the computational cost and other information of how useful the code developed is.