This work presents a near-field microwave resonant sensor combining with a micro-channel for detecting biological cells. The hairpin biosensor with a high-Q dielectric resonator allows the detection of a small variation of DUT in the microchannel by measuring the scattering parameters responses at resonance of around 2.2 GHz. The sensor was constructed by using microelectromechanical-system (MEMS) technology. Cu electroplating technique was used to fabricate 14-μm-thick Cu electrodes to reduce the transmission loss caused by the rough surface of electrodes and to match the size of cells. Measurements of Dulbecco's modified Eagle's medium (DMEM) and B16F10 melanoma cells (mus musculus skin melanoma) were performed. The results showed that the thick Cu electrodes provided two advantages: loss reduction and cell detection sensitivity. These analysis results are helpful for further applications such as cell trapping, measurement, and characteristics.