A comprehensive understanding of elementary processes in individual single cells in development or adulthood is a challenging task, while essential in several molecular biology disciplines like in neural, stem cell and developmental biology. In this work we present an innovative transfection method with respect to already existing devices. The novelty comprises the advantage to address individual single adherent cells simultaneously, delivering one or more compounds or macromolecules to different single cells at the same time (multisite electroporation) or to the same cell at different times (serial electroporation) permitting a temporally controlled transfection. For our experiments we used several primary and immortalized cell lines (HDF, BAEC, NHEK, CHO, 3T3, COS). Cells were grown by standard culture procedures, directly on a 61 gold microelectrodes array integrated in a microfabricated biochip. Through a PC driven system, single cells were stimulated in the presence of different molecules of interest. We assessed the possibility to tune the delivery to individual (single) cells of different compounds such as 23bp fluorescein labeled DNA oligonucleotides, pcDNA3.1-ECFP, custom siRNA for ECFP silencing, fluorescein-labeled antibodies and other reporter molecules. This method will provide a cell-based assay as a powerful tool to screen various molecules giving the possibility to accurately restrict the transfected area and to follow the behaviour of the targeted cells. The technique can be used to get further insights not only into gene expression/silencing, but also into other areas of research such as single cell analysis, single cell biophysics, cell-cell signaling and microkinetics studies. For example, it will provide a useful tool for studying gene expression by simply applying the electric pulse in the presence of various stimuli (structural proteins, genetic construct, transcription factors and cell-cycle regulators) and observing the cell reaction directly under microscope revealing cellular and molecular events of biology in real time.