Before assistive reproductive treatment will be started for a couple that is childless by default, the cause of the fertility disorder needs to be investigated for both the man as well as the woman. For the man this implies that the quality of his semen needs to be known. Currently, at the hospital laboratories the semen analysis is performed manually using a microscope or a CASA system, making it time‐consuming and subjective or expensive. To overcome these disadvantages and make it applicable for testing in the private environment of the man, a start has been made towards the development of a fertility chip for semen analysis, which is described in this thesis. In the project a microfluidic chip has been developed that enables us to determine the concentration of spermatozoa. For this a sample is guided along a planar electrode pair in a microchannel and by using electrical impedance measurements the spermatozoa are individually detected. By the addition of a known concentration of beads to the sample, we were able to determine the spermatozoa concentration without knowing the actual flow speed. Since the planar electrode configuration used in the concentration chip has some disadvantages due to an inhomogeneous electrical field, a parallel electrode configuration has also been developed and tested. Another microfluidic chip has been developed for the determination of the motility of spermatozoa. Preliminary results indicate that it is possible to use laminar flow profiles in combination with electrical impedance measurements to determine the motility of the spermatozoa in the semen sample. Besides the electrical impedance measurements, we recently developed a compact system for optical fluorescence detection on chip.