The present disclosure relates to a multi-purpose instant chiller-heater apparatus (100) having a housing (102) with a top portion, a bottom portion and a number of side portions. The multi-purpose instant chiller-heater apparatus (100) further includes a hollow tube structure (104) positioned within the housing (102) for passing the liquid to be heated or cooled through it. The hollow tube structure (104) is provided with an inlet (112) at one end of the hollow tube structure (104) for receiving the liquid and an outlet (114) at another end of the hollow tube structure (104) for providing chilled or heated liquid. The housing (102) is configured to store a heating or cooling means to heat or cool the liquid passing through the hollow tube structure (104) positioned inside the housing (102). The housing (102) is provided with an insulator layer for preventing heat exchange between its interior and exterior. The liquid passing through the hollow tube structures (104) inside the housing (102) is cooled or heated to a desired temperature and is discharged through the outlet (114) of the housing (102).