In this study, we developed an electrochemical cellular chip for continuous monitoring of histamine release at single cell level. The cells were individually accommodated and stabilized inside a microwell electrode (MWE), and then the released histamine was electrochemically detected by the MWE. We employed KU-812 cells (ECACC no. 90071807) as a cell model, and a spiked amperogram was observed in accordance to the exocytotic event of histamine release. In our experiment, the investigated cells were stimulated with high K+ solution which increases a cytosolic Ca2+ influx. The amperograms (+0.6 V vs. Ag/AgCI) of single KU-812 cell with and without stimulation were compared, and an amperogram with higher spiked current were found in high K+ solution. Our result shows that a feasible application for the cell secretion measurement by using this device.