Abstract The influence of temperature distribution on the melting process in a ceramic differential scanning micro-calorimeter (MC-DSC) is shown. The MC-DSC chip is manufactured in low temperature co-fired ceramics technology (LTCC) as a three-dimensional device that includes all functions of a conventional DSC device. This study deals with the simulation-based optimization of the heater geometry for the second MC-DSC-chip generation to improve both sensitivity and selectivity. The influence of the heater geometry improvement was evaluated by simulation of the melting process of indium. The results suggest both higher sensitivities and higher selectivities.