In this master thesis, deformation and stress occurring in circular cross-sectioned porous cantilever beam loaded to bending, are analysed. A Gyroid cell is defined as the main cell of a porous structure, and is also the main representative of the group called triply periodic minimal surface lattice structures. In order to conduct analitical and numerical calculations as well as experimental testing using strain gauge, first step is to define geometry and material of the cantilever beam, and than to make a model of the beam in SolidWorks and nTopology programs. Analitical calculation, considering changeable values of the moment of inertia of the cross section because of the porousity of the structure, is made in Excel for every 0,1 mm of the beam length, but the used equations are given in chapter 4. The results of numerical calculation are taken from previously mentioned nTopology programe, where the model was firstly meshed with finite elements and than static analysis was made to obtain the requested results. Furthermore, to conduct the experimental testing, porose cantilever beam was made using FDM 3D printing technology and the deformations were measured using strain gauges. The results of displacement, stress and deformation given by all three methods were collected, compared and shown. Considering the calculated equivalent stress field, in the last chapter porous cantilever beam was optimized in order to create more even stress distribution and to decrease the weight of the beam.