My PhD study is focused on fabrication and investigation of graphene-based sensors. Preparation of graphene by the mechanical exfoliation and characterization its quality by atomic force microscopy, Raman scattering and reflectometry belong to experiences obtained during my master study. Main part of my work is creation of nanostructures by the electron beam lithography (EBL), using focused ion beam (FIB) or electron beam induced deposition (EBID). These methods are used for fabrication of metal contacts and shaping the graphene produced by our group (exfoliated graphene, CVD graphene and graphene oxide). Thereafter electrical transport properties are measured on graphene samples. In addition, the graphene resistivity response to relative humidity changes is studied.